End effectors, surgical stapling devices, and methods of using same

ABSTRACT

An end effector for use by a surgeon to staple an anatomical structure of a patient during a surgical procedure includes an anvil and a cartridge. Each of the anvil and the cartridge has a face that is positionable on the anatomical structure. The anvil is coupled to the cartridge at first and second ends. The anvil is movable relative to the cartridge to define a first gap between the faces at the first ends that is different from a second gap between the faces at the second ends.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional applicationSer. No. 15/633,399, filed Jun. 26, 2017, which was a continuation ofU.S. Non-Provisional application Ser. No. 15/129,366, filed Sep. 26,2016, now U.S. Pat. No. 9,724,096, which was a National StageApplication under 35 U.S.C. § 371 of PCT International Application No.PCT/US2015/022990, filed Mar. 27, 2015, which claims the prioritybenefit of U.S. Provisional Patent App. No. 61/972,274, filed Mar. 29,2014, and U.S. Provisional Patent App. No. 62/046,726, filed Sep. 5,2014, each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The invention relates to surgical staplers, and more particularly to endeffectors and stapling devices and methods of using those devices inmedical procedures.

BACKGROUND

Obesity, as a disease, affects a significant portion of the world'spopulation. Obesity often leads to multiple chronic medical conditionsand premature death from cardiovascular events and cancer. The U.S.Centers for Disease Control and Prevention (“CDC”) reports that over 33%of the U.S. population is obese, with a body mass index (“BMI”) of over30, and another 35-40% of the population is overweight, with a BMI of25¬30. The CDC reports that the percent of the population being eitheroverweight or obese by 2018 will be 75%. The CDC also reports thatobesity directly costs the U.S. economy $147 billion currently, andprojects that the costs will approach $315 billion by 2020. The increasein obesity and the financial impact on the local economy is not limitedto the United States but impacts many countries throughout the world.

Obesity has environmental, genetic, and behavioral origins but isintractable to most medical and behavioral interventions. Weight loss,or bariatric, surgery seems to be the only effective long-term treatmentoption for patients with a BMI greater than 35. Despite the 20 millionpatients who are eligible for weight loss surgery in the United States,the number of procedures per year has plateaued at about 200,000,essentially eliminating any meaningful public health effect of thesurgery.

In recent years, laparoscopic vertical sleeve gastrectomy has emerged asa procedure that is safe and effective for patients who are eligible forweight loss surgery. Laparoscopic surgery is a form of minimallyinvasive surgery inside of the abdominal cavity performed at a distanceby the surgeon. Laparoscopic surgery instrumentation is designed to fitthrough small incisions in the abdominal wall, typically 5 mm to 15 mmin diameter. The abdominal access sites are maintained by cannulae, ortrocars, that are designed to maintain pressure in the abdominal cavitywith valves that seal around an instrument shaft. Videoscopic guidancemay be used throughout the surgery. Since its introduction in 2003 as astand-alone surgery, vertical sleeve gastrectomy has been studiedextensively. It is now widely accepted as the surgery that should beoffered to most morbidly obese patients over laparoscopic adjustablegastric banding and laparoscopic Roux-en-Y gastric bypass. The surgeryhas been adopted by most bariatric surgeons and is now one of the mostcommonly used procedures to achieve effective weight loss.

During a vertical sleeve gastrectomy, approximately 80% of the stomachis removed and the remaining pouch is based on the less distensiblelesser curve of the stomach. The fundus of the stomach, which is formedby the upper curvature of the organ, is the most crucial portion of thestomach that is removed. The resultant gastric pouch generally should beabout 80 mL to about 820 mL in volume, should not be narrowed at theincisura angularis, should be as straight as possible to avoidobstruction from spiraling or zigzagging, should be about 0.5 cm toabout 2 cm away from the gastro esophageal junction, and should be about2 cm to about 10 cm away from the pylorus.

A vertical sleeve gastrectomy is typically performed using standardlaparoscopic equipment. The greater curvature of the stomach ismobilized by using vessel-sealing devices to seal the gastric branchesof the gastro epiploic vessels and the short gastric vessels. Theposterior adhesions of the stomach are also divided so the stomach isfully mobilized while the blood supply to the lesser curvature remainsintact. The left crus of the diaphragm is an important landmark toensure the fundus has been fully mobilized.

Following mobilization of the stomach and repair of any hiatal herniathat may be present, a calibration tube or bougie is typicallyintroduced into the stomach through the mouth. The bougie is insertedthrough the mouth, down the esophagus, and into the stomach, where it isused as a point of reference in order to help align the initial staplefire. The bougie acts as a left-hand landmark, which the surgeon uses tovisualize the path of the staple line. A surgeon creating a sleevegastrectomy staple line will estimate 2.0 cm away from the lessercurvature of the stomach and visually orient the stapler. As constantdiameter bougies cannot be used to facilitate orienting the stapler,only surgeon experience and estimation is used. At the top of the stapleline, it is important to not divide part of the esophagus or the ‘slingfibers’ of the cardia, which participate in the physiologic anti-refluxaction of the lower esophageal sphincter. Surgeons must use visual cuesto ensure that the staple line is a safe distance away from the gastroesophageal junction.

Resection is accomplished by a series of applications of a laparoscopiclinear surgical stapler, which are also referred to as endocuttersurgical staplers. The staplers that are most commonly used for sleevegastrectomy are no more than 60 mm in length and include an integratedcutting blade, an anvil, and a cartridge, where the anvil and cartridgeare parallel in the longitudinal direction. Conventional endocutterstaplers have double or triple staggered rows of staples on either sideof the cutting blade. Each staple application places two or threestaggered rows of staples into the tissue on either side of the cuttingblade. For sleeve gastrectomy, the average number of staple fires perprocedure is 3 to 7 in order to create a continuous resection line. Thisresults in a resection line that is about 15 cm to about 37 cm onaverage.

Proper alignment between the anvil and cartridge is very importantduring staple formation. Surgical staplers must have alignment in the x,y, and z axes to be able to form B-shaped staples. The alignment of theanvil and cartridge must be maintained along the length of the stapler.The anvil may be deflected during staple formation due at least in partto the forces of tissue and staple formation on the anvil. Thisdeflection has limited the lengths of staplers. More specifically, thelonger the stapler is, the more the tip of the stapler tends to deflect.This often results in a gap that is too wide to form staples appropriatefor the thickness of the tissue to be stapled.

Currently, surgeon training, experience, and trial and error are theonly tools used to aid the surgeon in determining the path of theresection line in a vertical sleeve gastrectomy. Only after applying thestapler to begin creating the resection line is the resultant stomachanatomy demonstrated. Before beginning stapling, the surgeon mustattempt to envision the resultant anatomy of the stomach. Further, thesurgeon must actively and accurately control the stapler during theresection to produce the desired resection line. Because the thicknessof the stomach tissue varies at the antrum, the body, and the fundus,different staple leg lengths are typically used. This requires thestapler to be removed from the patient between firings to load thestapler with a new cartridge having staples with an appropriate leglength. Generally, one or more applications of cartridges includingstaples with a longer closed leg length are followed by one or moreapplications of cartridges including staples with a shorter closed leglength. This serial cartridge application can lead to a less thanoptimal anatomic appearance of the segmented staple line, such as a“zig-zagging” or spiraling line.

There is wide variability in the size and type of calibration tube, orbougie, used by surgeons to size the remaining gastric sleeve. Somesurgeons use an endoscope (30 French or 1 cm in diameter) while othersuse a large mercury-weighted bougie (60 French or 2 cm in diameter). Ina large meta-analysis, there was no difference in weight loss whenbougie sizes of less than 40 and greater than 40 were used. Theresection line is important in sleeve gastrectomy because the amount ofweight loss and subsequent medical complications may be a direct resultof the quality of the resultant anatomy. The resultant anatomy isdetermined by the staple line created by the surgeon during thegastrectomy. Negative consequences related to the quality of the stapleline may include, for example, gastro esophageal reflux, weight lossfailure, weight regain, food intolerance, resection line bleed, andleak.

Leaks are the most concerning complication of a vertical sleevegastrectomy. In large pooled databases, the leak rate is approximately0.3 to 2%. Leak is thought to be prevented by making a straight stapleline that avoids crossing cartridge applications, has no narrow segments(particularly at the incisura angularis), is about 1 cm from the gastroesophageal junction, and has a squared-off final application. Generallyspeaking, leak is not prevented by sewing over the staple line or usingstaple line buttress material in the resection line. Leak is thought tobe more a result of poor resultant stomach anatomy. Poor anatomy is adirect result of the shortcomings of the calibration equipment andtechnique used to create the staple line. Conventional calibration tubesspecifically designed for use in a sleeve gastrectomy may provide someuser benefits, but fail to reliably produce the proper geometry of theresultant anatomy from the vertical sleeve gastrectomy.

Accordingly, new apparatuses and methods are needed to address theshortcomings of existing apparatuses and methods. More particularly,improved apparatuses and methods are needed that improve the consistencyand quality of the staple line created during a medical procedure, suchas a vertical sleeve gastrectomy.

SUMMARY

An end effector for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure addresses these and othershortcomings and, in one embodiment, the anatomical structure has afirst side and a second side and the end effector includes an anvil thatincludes a first end, a second end, and a face that is positionable onthe first side of the anatomical structure. The end effector furtherincludes a cartridge that is configured to house a plurality of staplesand that includes a first end, a second end, and a face that ispositionable on the second side of the anatomical structure. The firstend of the cartridge is movably coupled to the first end of the anvil,and the second end of the cartridge is movably coupled to the second endof the anvil. The anvil is movable relative to the cartridge to define afirst gap between the faces at the first ends that is less than a secondgap between the faces at the second ends.

In one embodiment, the decrease from the first gap to the second gap isdetermined by an angle of from about 0.1° to about 1°.

In one embodiment, the first gap is from about 1.5 mm to about 3.3 mm.

In one embodiment, the second gap is from about 2.0 mm to about 5.0 mm.

In one embodiment, the first ends define a distal end of the endeffector and the second ends define a proximal end of the end effector.

In one embodiment, the end effector further includes a shim having awedge-shape coupled to the face of at least one of the anvil and thecartridge and defining at least one of the first gap and the second gap.

In one embodiment, each face defines a width and the shim extends thewidth of at least one of the faces.

In one embodiment, a thickness of the shim varies across a width of theshim.

In one embodiment, the end effector further includes a shim having awedge-shape coupled to the face of at least one of the anvil and thecartridge and defining each of the first gap and the second gap.

In one embodiment, the end effector further includes a shim that iscoupled to the face of at least one of the anvil and the cartridge, theshim having a first end, a second end, and a thickness, the thickness ofthe shim at the first end being different than the thickness of the shimat the second end.

In one embodiment, at least one of the faces of the anvil and thecartridge has a stepped configuration including at least two segmentsthat are offset from one another. One segment defines the first gap andthe other segment defines the second gap.

In one embodiment, the cartridge includes a plurality of staples and anopen leg length of each of the staples in each segment is the same.

In one embodiment, the cartridge includes staples each having an openleg length and the open leg length of one staple in one segment isdifferent from the open leg length of one staple in the other segment.

In one embodiment, the cartridge includes a plurality of staple driverseach having a height and the height of at least two staple drivers aredifferent in a direction from the first end to the second end of thecartridge.

In one embodiment, the cartridge includes staples, each staple having anopen leg length, the open leg length of at least one staple is differentfrom the open leg length of another staple along a length of thecartridge from the first end to the second end.

In one embodiment, the open leg lengths of the staples are randomlydistributed.

In one embodiment, a distribution of the open leg lengths of the staplesis based on a probable tissue thickness along the anatomical structurefrom the first end to the second end.

In one embodiment, the staples are divided into at least two zones ofstaples. The staples are arranged in at least one row and at least onecolumn in each zone. The open leg length of one staple in one zonediffers from the open leg length of another staple in the other zone.

In one embodiment, the cartridge has a first edge and a second edge andone staple in the zone adjacent the first edge has a greater open leglength than another staple in the zone adjacent the second edge.

In one embodiment, the cartridge includes a plurality of staples dividedinto at least two zones, and a crown length of one staple in one zonediffers from a crown length of another staple in the other zone.

In one embodiment, the cartridge includes a plurality of staples dividedinto at least two zones of staples, and a gauge of one staple in onezone differs from a gauge of another staple in the other zone.

In one embodiment, the cartridge includes a plurality of magazinesconfigured to be selectively inserted and removed from the cartridge,each magazine including a plurality of staples arranged in one or morerows and one or more columns.

In one embodiment, a length of at least one magazine is from about 5 mmto about 250 mm.

In one embodiment, at least one magazine includes a channel for acutting blade with at least one column of staples on each side of thechannel.

In one embodiment, the magazines include an interlock feature.

In one embodiment, the interlock feature includes a projection on one ofthe magazines and a recess on another of the magazines, the projectionbeing configured to be received in the recess when the magazines areadjacent to each other in the cartridge.

In one embodiment, the cartridge includes a plurality of staplesarranged in rows and columns, each staple having an open leg length, thestaples in each column having about the same open leg length. Each ofthe anvil and the cartridge has a first edge and a second edge, theanvil being movable relative to the cartridge to define a first edge gapbetween the faces at the first edges that is less than a second edge gapbetween the faces at the second edges.

In one embodiment, the end effector further includes an alignmentmechanism configured to facilitate alignment between the anvil and thecartridge as the anvil is moved toward the cartridge.

In one embodiment, the alignment mechanism includes a knife that ispartially housed in the cartridge and that has a first flange, a secondflange, and a web connecting the first and second flanges and includinga cutting edge. The alignment mechanism further includes a recess in theanvil face that is configured to receive the first flange. The alignmentmechanism further includes a first slot in the anvil that is open to theanvil face and to the recess and that is configured to slidably receivethe web during cutting of the anatomical structure with the cutting edgeand a second slot in the cartridge that is open to the cartridge faceand that is configured to slidably receive the web during cutting of theanatomical structure.

In one embodiment, the anvil has a first guide channel open to the firstslot, the cartridge has a guide channel open to the second slot, and thefirst and second guide channels are parallel.

In one embodiment, the anvil face and the cartridge face are notparallel.

In one embodiment, at least one of the anvil face and the cartridge facehas a stepped configuration including at least two segments that areoffset from one another, one segment defines the first gap and the othersegment defines the second gap.

In one embodiment, one of the first and second flanges has a V-shapedcross-section.

In one embodiment, the staples have two legs and a crown having amidline and the staple pockets are configured to bend the two legs pastthe midline of the crown when the end effector is actuated.

In one embodiment, each of the anvil and the cartridge has a first edgeand the end effector further includes a spacer coupled to the first edgeof at least one of the anvil and the cartridge and being configured toabut an anatomical feature to space the end effector apart from theanatomical feature by a known distance.

In one embodiment, the end effector is insertable through a trocar.

In one embodiment, the end effector further includes a flexible memberthat movably couples the first end of the anvil to the first end of thecartridge.

In one embodiment, at least one of the anvil and the cartridge slidablyreceives the flexible member when the end effector is clamped on to theanatomical structure.

In one embodiment, the flexible member is anchored to the anvil.

In one embodiment, the flexible member is anchored to the cartridge.

In one embodiment, the end effector further includes a tensioning deviceoperable by the surgeon for selectively tensioning the flexible memberto provide at least a portion of the clamping force on the anatomicalstructure.

In one embodiment, each of the anvil and the cartridge is insertablethrough a trocar and the end effector is remotely operable from outsidethe patient to clamp the end effector to the anatomical structureaccording to the first gap and the second gap

A stapling device for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure, in one embodiment, theanatomical structure has a first side and a second side and theendocutter stapling device includes an end effector and a manipulatorthat is configured to be accessible to the surgeon outside of thepatient and that includes a shaft coupled to the end effector and aclamping mechanism for selectively moving the anvil and the cartridgetoward one another to clamp the anatomical structure. The device furtherincludes a flexible member that extends through the shaft to the endeffector and is operably coupled to at least one of the anvil and thecartridge and to the clamping mechanism such that operating the clampingmechanism withdraws the flexible member from the end effector and clampsthe anatomical structure between the anvil and the cartridge.

In one embodiment, the clamping mechanism is capable of selectivelytensioning the flexible member to clamp the anvil and the cartridge tothe anatomical structure with a first stage clamping force that permitsthe end effector to be repositioned relative to the anatomicalstructure.

In one embodiment, the first stage clamping force is between about 0.1g/mm2 and about 4 g/mm2.

In one embodiment, the clamping mechanism is capable of selectivelytensioning the flexible member to clamp the anvil and the cartridge tothe anatomical structure with a second stage clamping force thatsubstantially prevents the end effector from moving relative to theanatomical structure during the medical procedure.

In one embodiment, the second stage clamping force is between about 4g/mm2 and about 70 g/mm2.

In one embodiment, the manipulator includes a handpiece that at leastpartially houses the clamping mechanism, the clamping mechanism furtherincludes a lever that is pivotable relative to the handpiece and isoperable to activate the clamping mechanism.

In one embodiment, the clamping mechanism includes a first push bar thatis pivotably coupled to the lever, a second push bar that is pivotablycoupled to the first push bar, and a pin that is coupled to the secondpush bar, the flexible member extending around the pin. Rotation of thelever relative to the handpiece moves the pin and withdraws the flexiblemember from the end effector

In one embodiment, the manipulator includes a stapling mechanism thathas an actuator coupled to an actuator plate that is slidable relativeto the end effector and at least one wedge coupled to the actuatorplate. Activating the actuator slides the actuator plate and the atleast one wedge in the direction of the end effector to force the wedgeinto engagement with staples.

In one embodiment, the actuator is a thumb plate.

In one embodiment, the manipulator includes a cutting mechanism that isconfigured to cut the anatomical structure and is coupled to theactuator plate and, when the actuator is engaged, the stapling mechanismbegins stapling the anatomical structure prior the cutting mechanismcutting the anatomical structure.

An end effector for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure, in one embodiment, theanatomical structure has a first side and a second side and the endeffector includes an anvil that includes a first end, a second end, aface that is positionable on the first side of the anatomical structure,and a first edge. The end effector further includes a cartridge that isconfigured to house a plurality of staples and that includes a firstend, a second end, a face that is positionable on the second side of theanatomical structure, and a first edge. The first end of the cartridgeis movably coupled to the first end of the anvil. The end effectorfurther includes a spacer configured to be coupled to the first edge ofat least one of the anvil and the cartridge.

An end effector for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure, in one embodiment, theanatomical structure having a first side and a second side and the endeffector includes an anvil that includes a first end, a second end, aface that is positionable on the first side of the anatomical structure,the face defining a width, a first edge, and a second edge. The endeffector further includes a cartridge that includes a plurality ofstaples arranged in rows and columns, each staple having an open leglength, the staples in each column having about the same open leglength, a first end, a second end, and a face that is positionable onthe second side of the anatomical structure, the face defining a firstedge, a second edge, and a width between the first edge and the secondedge. The first end of the cartridge is movably coupled to the first endof the anvil, the anvil being movable relative to the cartridge todefine a first edge gap between the faces at the first edges that isless than a second edge gap between the faces at the second edges. Whenthe end effector is positioned on the anatomical structure, the firstedge gap linearly increases to the second edge gap.

An end effector for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure, in one embodiment, theanatomical structure having a first side and a second side and the endeffector includes an anvil that includes a first end, a second end, aface that is positionable on the first side of the anatomical structure,the face defining a width, and a first edge. The end effector furtherincludes a cartridge that is configured to house a plurality of staplesand that includes a first end, a second end, a face that is positionableon the second side of the anatomical structure, the face defining awidth, and a first edge. The first end of the cartridge is movablycoupled to the first end of the anvil. The end effector further includesa shim that is coupled to the face of at least one of the anvil and thecartridge, the shim having a first edge, a second edge, and a thickness,the thickness of the shim at the first edge being different than thethickness of the shim at the second edge.

In one embodiment, the shim extends the width of at least one of thefaces.

In one embodiment, a thickness of the shim varies across the width ofthe shim.

An end effector for use by a surgeon to staple an anatomical structureof a patient during a surgical procedure, in one embodiment, theanatomical structure has a first side and a second side and the endeffector includes an anvil that includes a first end, a second end, aface that is positionable on the first side of the anatomical structure.The end effector further includes a cartridge that includes a pluralityof staple channels arranged in one or more rows and one or more columns,is configured to house a plurality of staples individually in the staplechannels, and that includes a first end, a second end, and a face thatis positionable on the second side of the anatomical structure, the rowsextending from the first end toward the second end. The first end of thecartridge is movably coupled to the first end of the anvil. The endeffector further includes a shim that is coupled to the face of at leastone of the anvil and the cartridge, the shim covering less than all ofthe rows of the staple channels.

A cartridge for use in an end effector having an anvil, the end effectorbeing for use by a surgeon to staple an anatomical structure of apatient during a surgical procedure, in one embodiment, the anatomicalstructure has a first side and a second side and the cartridge includesa cartridge body defining a plurality of staple channels. The cartridgefurther includes a plurality of staples arranged in rows and columns,each staple having an open leg length and a crown and being housed inone of the staple channels. The open leg length of one of the staplesdiffers from the open leg length of another of the staples in alongitudinal direction along the rows. The open leg length of thestaples is selected based on a probable tissue thickness along theanatomical structure from the first end to the second end.

In one embodiment, the cartridge body is divided into at least twozones, each zone having a plurality of staples arranged in at least onerow and at least one column, each staple having an open leg length. Theopen leg length of one staple in one zone differs from the open leglength of one staple in the other zone.

In one embodiment, the cartridge includes a plurality of magazinesconfigured to be selectively inserted and removed from the cartridge,each magazine including a plurality of staples arranged in one or morerows and one or more columns.

In one embodiment, a length of at least one magazine is from about 5 mmto about 250 mm.

In one embodiment, at least one magazine includes a channel for acutting blade with at least one column of staples on each side of thechannel.

In one embodiment, the magazines include an interlock feature.

In one embodiment, the interlock feature includes a projection on one ofthe magazines and a recess on another of the magazines, the projectionbeing configured to be received in the recess when the magazines areadjacent to each other in the cartridge.

A method of stapling an anatomical structure during a surgical medicalprocedure, in one embodiment, includes

In one embodiment, inserting the end effector of claim 1 through atrocar into a patient adjacent the anatomical structure, the cartridgeincluding a plurality of staples, positioning the anvil and thecartridge on opposing sides of the anatomical structure, clamping theend effector to the anatomical structure at the first ends of the anviland the cartridge and the second ends of the anvil and the cartridge tosecure the position of the end effector relative to the anatomicalstructure, and actuating the end effector to staple the anatomicalstructure.

In one embodiment, the method further includes positioning a clampadjacent to the anatomical structure, and wherein positioning the anviland the cartridge includes positioning at least one of the anvil andcartridge adjacent the clamp.

In one embodiment, the staples having an open leg length are arranged inrows and columns and the open leg length of each of the staples is thesame in each column, and actuating the end effector includes forming afirst row of staples and a second row of staples, the staples in thefirst row having a greater closed leg length than the staples in thesecond row

In one embodiment, each of the anvil and the cartridge have a first edgeand a second edge and clamping the end effector to the anatomicalstructure includes compressing the anatomical structure more at thefirst edges than at the second edges.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description given below, serve to explain the invention.

FIG. 1 depicts the anatomy of a stomach.

FIG. 2A is an elevation view of an end effector of an endocutterstapling device according to one embodiment of the invention.

FIG. 2B is an elevation view of the end effector of FIG. 2A positionedon the stomach.

FIG. 2C is an elevation view of the end effector of FIG. 2A duringresection of a portion of the stomach.

FIG. 2D is an elevation view of the end effector of FIG. 2A followingresection of a portion of the stomach.

FIG. 2E depicts the stomach anatomy resulting from a vertical sleevegastrectomy.

FIG. 3 is a perspective view of an endocutter stapling device accordingto one embodiment of the invention.

FIG. 4 is a perspective view of the endocutter stapling device of FIG. 3with an end effector shown in an opened position.

FIG. 4A is an enlarged perspective view of the end effector shown inFIG. 4.

FIG. 5 is a disassembled perspective view of the endocutter staplingdevice of FIG. 3.

FIG. 6 is a cross-sectional view of the endocutter stapling device takenalong section line 6-6 of FIG. 4.

FIG. 6A is a cross-sectional view of the end effector shown in FIG. 4Ataken along section line 6A-6A.

FIG. 7 is a cross-sectional view of the endocutter stapling device takenalong section line 7-7 of FIG. 3.

FIG. 7A is a cross-sectional view of the endocutter stapling devicetaken along section line 7A-7A in FIG. 7.

FIG. 8 is an enlarged perspective view of a handpiece of the endocutterstapling device of FIG. 3.

FIG. 9 is an enlarged view of the encircled area 9 shown in FIG. 8.

FIG. 10 is an enlarged view of the encircled area of the endocutterstapling device of FIG. 7.

FIG. 10A is a cross-sectional view of the endocutter stapling devicetaken along section line 10A-10A in FIG. 10.

FIG. 10B is an enlarged view of the endocutter stapling device similarto FIG. 10 during use of the endocutter stapling device.

FIG. 10C is a perspective view of a knife and a pair of wedges of theendocutter stapling device of FIG. 3.

FIG. 10D is a perspective view of the knife and the pair of wedges shownin FIG. 10 during use of the endocutter stapling device.

FIG. 11 is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 12A is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 12B is a schematic elevation view of the end effector of FIG. 12Apositioned on a stomach after actuation of an endocutter stapling deviceaccording to one embodiment of the invention to complete a staple line.

FIG. 12C is a schematic elevation view of stomach anatomy resulting fromthe use of an endocutter stapling device according to one embodiment ofthe invention.

FIG. 13 is a perspective view of a shim according to one embodiment ofthe present invention.

FIG. 14A is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 14B is a schematic elevation view of the end effector of FIG. 14Apositioned on a stomach after actuation of an endocutter stapling deviceaccording to one embodiment of the invention to complete a staple line.

FIG. 15A is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 15B is a schematic elevation view of the end effector of FIG. 15Apositioned on a stomach after actuation of an endocutter stapling deviceaccording to one embodiment of the invention to complete a staple line.

FIG. 16A is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 16B is a schematic elevation view of the end effector of FIG. 16Apositioned on a stomach after actuation of an endocutter stapling deviceaccording to one embodiment of the invention to complete a staple line.

FIG. 17A is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 17B is a schematic elevation view of the end effector of FIG. 17Apositioned on a stomach after actuation of an endocutter stapling deviceaccording to one embodiment of the invention to complete a staple line.

FIG. 18 is a schematic elevation view of an end effector according toone embodiment of the present invention.

FIG. 19 is a schematic elevation view of a cartridge according to oneembodiment of the present invention.

FIG. 20A is a schematic elevation view of an end effector including thecartridge of FIG. 19.

FIG. 20B is a schematic elevation view of the end effector of FIG. 20Aduring compression of the stomach.

FIG. 20C is a schematic elevation view of the end effector of FIG. 20Afollowing stapling of the stomach.

FIG. 21 is a schematic elevation view of a cartridge according to oneembodiment of the present invention.

FIG. 22 is a schematic elevation view of a cartridge according to oneembodiment of the present invention.

FIG. 23 is a schematic elevation view of a cartridge according to oneembodiment of the present invention.

FIGS. 23A and 23B are cross-sectional views of the cartridge of FIG. 23taken along section line 23A-23A and 23B-23B, respectively.

FIG. 23C is a perspective view of an arrangement of staples in acartridge according to one embodiment of the invention.

FIG. 24A is a plan view of a cartridge according to one embodiment ofthe present invention.

FIG. 24B is an enlarged perspective view of a magazine of FIG. 24Aillustrating the assembly of the cartridge.

FIG. 24C is an enlarged perspective view of a portion of the cartridgeof FIG. 24A following assembly according to FIG. 24B.

FIG. 25 is a plan view of a cartridge according to one embodiment of thepresent invention.

FIG. 26A is a cross-sectional view of an end effector according to oneembodiment of the invention taken along section line 26A-26A of FIG. 25.

FIG. 26B is a cross-sectional view of an alternative cartridge accordingto one embodiment of the invention similar to that shown in FIG. 26A.

FIGS. 27A and 27B are cross-sectional views of an end effector accordingto one embodiment of the invention before and after stapling,respectively.

FIG. 27C is a cross-sectional view of the staple line after actuation ofan endocutter stapling device according to one embodiment of theinvention to complete a staple line.

FIG. 28A is a cross-sectional view of an end effector according to oneembodiment of the present invention.

FIG. 28B is a cross-sectional view of the staple line after actuation ofthe end effector shown in FIG. 28A according to one embodiment of theinvention to complete a staple line.

FIG. 29 is a plan view of a cartridge according to one embodiment of theinvention.

FIG. 30A is a cross-sectional view of an end effector including acartridge shown in FIG. 29 taken along section line 30A-30A.

FIG. 30B is a cross-sectional view of an end effector similar to that ofFIG. 30A according to one embodiment of the present invention.

FIG. 30C is a cross-sectional view of the end effector of FIG. 30Bduring stapling of a stomach according to one embodiment of theinvention.

FIGS. 31 and 32 are cross-sectional views of end effectors according toembodiments of the present invention.

FIGS. 33-36 are elevation views of end effectors according to variousembodiments of the present invention.

FIGS. 37A and 37B are an elevation view and a plan view, respectively,of a staple according to one embodiment of the present invention.

FIGS. 38A and 38B are an elevation view and a plan view, respectively,of a staple according to one embodiment of the present invention.

FIGS. 39A and 39B are a cross-sectional view and a plan view,respectively, of a staple pocket according to one embodiment of thepresent invention.

FIGS. 40A and 40B are a cross-sectional view and a plan view,respectively, of a staple pocket according to one embodiment of thepresent invention.

FIG. 41 is an elevation view of one embodiment of the present inventionfollowing resection of a stomach.

FIG. 42 is a perspective view of an end effector according to oneembodiment of the invention positioned on a stomach.

DETAILED DESCRIPTION

In its broadest aspects, embodiments of the present invention aredirected to a stapler for creating a staple line during a surgicalprocedure involving the resection of at least a part of an anatomicalstructure. For example, the stapler may be used in a vertical sleevegastrectomy procedure. The stapler may be a supplement to currentpractices of a sleeve gastrectomy, including the laparoscopic access andmobilization of the greater curvature of the stomach. As is described indetail below, embodiments of the stapler account for variations inthickness of the tissue and, in doing so, are believed to provide astaple line of improved integrity.

While embodiments discussed below involve the use of a stapler to createa staple line during a medical procedure, it should be recognized thatthe stapler may act as a surgical clamp independent of its use asstapler. Further, while embodiments discussed below involve the use ofthe stapler in a vertical sleeve gastrectomy procedure, the stapler mayalso be adapted for use in other procedures involving anatomicalstructures, such as organs other than the stomach or soft tissue. Forexample, the stapler may be used in a parenchymal resection, lung volumereduction surgery, or other procedures involving the lung. Further, thestapler may be useful in an anatomic resection such as a lobectomy, anon-anatomic parenchymal resection, or other procedures involving theliver. Moreover, a surgeon or other medical professional may benefitfrom using the stapler in a partial nephrectomy, total nephrectomy, orother procedures involving the kidney. During procedures involving ananatomical structure, the tissue of the anatomical structure may besealed. Thus, while aspects of the present invention may be illustratedin the context of a vertical sleeve gastrectomy, it should beappreciated that aspects of the invention may provide a benefit in ahost of medical procedures on anatomical structures and be adapted foruse in such medical procedures.

Now referring to the figures, FIG. 1 illustrates the anatomy of astomach 10 and a staple line 12, where the staple line 12 represents aresection line for a vertical sleeve gastrectomy. The stomach 10generally includes a proximal end 14, a distal end 16, an anterior side18, and a posterior side 20. As used herein, the proximal and distalends 14, 16 of the stomach 10 are described from the perspective of theoperative surgeon. A gastro esophageal junction 22 opens into thestomach 10 and is a common landmark in bariatric surgeries. An antrum 24and a fundus 26 are located adjacent the proximal and distal ends 14, 16of the stomach 10, respectively. The thickness of the stomach 10generally increases from the fundus 26 to the antrum 24. The thicknessof the stomach may also vary based on other factors. For example, malestomachs tend to have a greater thickness than female stomachs. Further,patients with a higher body mass index (“BMI”) tend to have stomachswith a greater thickness than stomachs of patients with a lower BMI. Thestaple line 12 therefore traverses the stomach 10 over a portion inwhich the thickness of the tissue changes. The fundus 26 and the sectionof the stomach 10 defined by the greater curvature 28 are generally theparts of the stomach 10 removed during a vertical sleeve gastrectomy.The desired location of the staple line 12 is about 0.5 cm to about 2 cmaway from the gastro esophageal junction 22 and about 2 cm to about 10cm away from the pylorus 32.

Following the gastrectomy, the remaining pouch is generally defined by alesser curvature 30 and the staple line 12 and presents a stomach with asignificantly reduced volume. In accordance with aspects of theinvention, staplers as described herein aid in forming high quality,consistent staple lines during a medical procedure, such as a verticalsleeve gastrectomy. In this regard, the staplers provide an accuratevisual indication of the staple line before the stapler has beenactuated. The visualization aspect of the disclosed staplers is believedto result in high quality and consistent staple lines that aresignificantly improved over staple lines produced by currentmethodologies. Furthermore, unlike the prior art, embodiments of thestapler account for tissue thickness variation, such as, thicknessvariations associated with the staple line 12, during clamping and/orstapling which is also believed to result in high quality and consistentstaple lines.

To these and other ends, and with reference to FIG. 2A, embodiments ofthe present invention may include an end effector 40 having an anvil 42and a cartridge 44 coupled to one another. As is described below inreference to FIGS. 2B-2E, the surgeon may forcibly drive the anvil 42and the cartridge 44 toward one another to clamp the stomach 10 betweenthe anvil 42 and the cartridge 44. The surgeon may close the anvil 42and the cartridge 44 remotely from the end effector 40. That is, nodirect manual access to the end effector 40 is required. For thisreason, the end effectors, as disclosed herein, may be designedspecifically for use in surgical procedures in which the organ isaccessed through a trocar.

According to one aspect, clamping onto the stomach 10 permits thesurgeon to be able to accurately position the end effector 40 andensures creation of a straight sleeve gastrectomy pouch. In theexemplary embodiment, and with reference to FIG. 2B, the anvil 42 may begenerally positionable on the anterior side 18 of the stomach 10, andthe cartridge 44 may be generally positionable on the posterior side 20of the stomach 10. The cartridge 44 may house a plurality of surgicalstaples and a knife, each described below, for forming the staple line12. The anvil 42 and the cartridge 44 may be coupled together via aflexible member 46 and collectively operate as clamping members forpurposes described below. The present invention is not limited to theillustrated arrangement. For example, the arrangement of the anvil 42and the cartridge 44 may be reversed such that the anvil 42 is coupledto a shaft and is positioned adjacent the posterior side 20 of thestomach 10 and the cartridge 44 is coupled to the anvil 42 via theflexible member 46 and is positioned on the anterior side 18 of thestomach 10 (not shown). Other alternative arrangements may also bepossible depending on the surgical procedure and the surgeon'spreference, among other factors. There are many ways to couple the anvil42 and the cartridge 44 and the invention is not limited to the flexiblemember shown. By way of example, many of the connection methodsdescribed in PCT Application No. PCT/US2014/070869, which isincorporated by reference herein in its entirety, may be utilized toconnect the anvil and the cartridge described herein.

In one embodiment, the surgeon, using standard laparoscopic instrumentsand graspers, may position the end effector 40 proximate the stomach 10as is shown in FIG. 2B. In this regard, FIG. 2B illustrates the endeffector 40 placed around the stomach 10 with the anvil 42 and thecartridge 44 coupled together with the flexible member 46 at both theproximal end 14 and the distal end 16 of the stomach 10. The length ofthe anvil 42 and the cartridge 44 may be sufficient for the anvil 42,the cartridge 44, and the flexible member 46 to encircle the stomach 10,as shown. The length of the anvil and/or the cartridge as describedherein is not particularly limited. By way of example and notlimitation, the length of each may measure from about 35 mm to about 350mm. The end effector 40 may be put in place and used with or withouthaving to mobilize the greater curvature 28. For example, a surgeon mayprefer to leave the greater curvature 28 attached to the omentum (notshown), which could improve stability of the stomach 10 during stapling.

As is described below, the flexible member 46 may be coupled to atensioning mechanism by which the anvil 42 and the cartridge 44 may bemoved toward one another and to provide a sufficient clamping force onthe stomach 10. Once the end effector 40 is properly positioned, as isshown in FIG. 2B, the surgeon may then engage the tensioning mechanism,described below, to compress the anvil 42 and the cartridge 44 on thestomach 10, as is shown by the arrow 50 in FIG. 2B. In this regard, theend effector 40 may be coupled to a device that houses the tensingmechanism for tensioning the flexible member 46. As the anvil 42 and thecartridge 44 are brought together, the flexible member 46 may align theanvil 42 with the cartridge 44. In this regard, the end effectorsdisclosed herein may be self-aligning due, in part, to coupling of theanvil 42 to the cartridge 44 at each end. Tensioning the flexible member46 may also compress the tissue. For instance, as the flexible member 46is tensioned, the distance between the anvil 42 and the cartridge 44decreases, and ultimately compresses the stomach 10. In accordance withembodiments of the invention, a gap between the anvil 42 and thecartridge 44 may vary when the surgeon clamps the stomach 10. As isdescribed in detail below, the variation in the gap may reflectvariation in the thickness of the tissue clamped between the anvil 42and the cartridge 44.

In one aspect of the invention, the end effector 40 may be positionedrelative to the stomach 10 using a two-stage clamping process in whichthe surgeon operates the tensioning mechanism to clamp the anvil 42 andthe cartridge 44 onto the stomach 10. In the first clamping stage, theanvil 42 and the cartridge 44 may be clamped onto the stomach 10 toprovide a threshold amount of resistance to unintentional movement ofthe end effector 40 relative to the stomach 10. For example, the rangeof clamping pressure in the first stage may be about 0.1 g/mm2 to about4 g/mm2. While preventing undesirable or unintentional movements of theend effector 40, the surgeon may move the end effector 40 to a desiredposition relative to the stomach 10 without significant difficulty.

In the second clamping stage, and with the end effector 40 in thedesired location relative to the stomach 10, the clamping force of theend effector 40 may be increased to effectively prevent or minimize theend effector 40 from moving relative to the stomach 10. For example, theclamping pressure in the second stage may be about 4 g/mm2 to about 70g/mm2. In an exemplary embodiment, the clamping pressure in the secondstage may be about 8 g/mm2. The upper limit to which the end effector 40may be clamped is selected so as to avoid any damage to the underlyingtissue being clamped but also allow for adequate tissue compression forstaple formation. This upper limit may be, for example, about 70 g/mm2.Additionally, the lower limit in the disclosed range of about 4 g/mm2represents a threshold clamping force below which constitutes the firststage clamping and above which constitutes the second stage clamping. Itwill be recognized that these values are merely exemplary and theparticular values may depend on several factors, including theanatomical structure being clamped. Thus, embodiments of the inventionare not limited to the range of values provided herein. In accordancewith embodiments of the invention, the gap between the anvil 42 and thecartridge 44 may vary across the longitudinal length of the end effector40 when the surgeon clamps the stomach 10 in the first and/or secondstage.

In an advantageous aspect of the invention, when the end effector 40 isplaced on the stomach 10 (e.g., in the first clamping stage as describedabove), the surgeon has a clear visualization of the intended results ofthe vertical sleeve gastrectomy prior to actually performing theresection of the stomach 10 at the staple line 12. Hence, the surgeonhas an indication of what the resultant stomach shape and volume definedby the lesser curvature 30 and the staple line 12 will likely be priorto stapling and/or cutting the stomach tissue. If the surgeon is notsatisfied with the indication of the expected stomach shape and volume,the surgeon may adjust and manipulate the location and the alignment ofthe end effector 40 prior to stapling and cutting the stomach 10. Thisis in contrast to current procedures, where the resection line isgenerally not well visualized prior to activating the stapler. Thus,according to current procedures, the ultimate outcome is less certain.It will be appreciated that the end effector 40 should be positionedsuch that it does not provide lateral stretching or tension of thestomach 10, which may create an undesirable environment for stapling andcutting. Using the end effector 40 ensures proper alignment of thestaple line 12 so that removing the fundus 26 occurs at a safe distanceaway from both the lesser curvature 30 and the gastro esophagealjunction 22. The result is a staple line that is squared off at thefundus 26 of the stomach to prevent or reduce the likelihood of necrotictissue development.

Once the end effector 40 is positioned and the anvil 42 and thecartridge 44 are compressed, the surgeon may activate a cutting andstapling mechanism, described below, to cut and staple the tissue usingthe end effector 40 until complete resection of the stomach 10 occurs,as is illustrated in the sequence of FIGS. 2C, 2D, and 2E. In oneembodiment, the surgeon may engage a release mechanism after completingthe resection of the stomach 10. This allows slack to be introduced inthe flexible member 46 such that the anvil 42 may be separated from thecartridge 44. Consequently, once the anvil 42 and the cartridge 44 areseparated, the end effector 40 may be removed from the abdominal cavity.

With reference to FIGS. 3-10D, the surgeon may operate the end effector40 above, including one or both of the anvil 42 and the cartridge 44,during a vertical sleeve gastrectomy procedure with a mechanical devicethat is operably coupled to the one or both of the anvil 42 and thecartridge 44. With specific reference to FIG. 3, in one embodiment, anendocutter stapling device 100 includes the end effector 40 operativelycoupled to a manipulator 102. With the endocutter stapling device 100,the surgeon may remotely operate the end effectors disclosed herein.While specific reference is made to the endocutter stapling device 100,other stapling devices may be utilized in accordance with the presentinvention including, for example, the endocutter stapling devicesdescribed in commonly owned U.S. application, which is incorporated byreference herein in its entirety.

As shown in FIG. 3, the manipulator 102 includes an elongate member orshaft 104 coupled to a handpiece 106 at one end and the end effector 40at the other end thereof. During a surgical procedure, the end effector40 and a portion of the shaft 104 may be inserted into the patient, suchas via a trocar. The surgeon may then manipulate the end effector 40and/or articulate the end effector 40 relative to the manipulator 102 toperform a procedure. Thus, embodiments of the present invention mayinclude mechanisms for effectuating a surgical procedure with the endeffector 40 (including clamping, stapling, and cutting tissue) and forallowing the end effector 40 to articulate relative to the shaft 104,each described below.

With reference to FIGS. 3, 4, and 4A, the anvil 42 and the cartridge 44are movably coupled together via the flexible member 46 as is describedabove. The flexible member 46 passes through hollow portions of theanvil 42 and the cartridge 44 and is movable relative to one or both ofthe anvil 42 and the cartridge 44. The flexible member 46 may beanchored to one of the anvil 42 or the cartridge 44, as is describedbelow. In the exemplary embodiment shown, the anvil 42 may be separatedfrom or brought closer to the cartridge 44 by extending or retractingthe flexible member 46. Retraction of the flexible member 46 moves theanvil 42 toward the cartridge 44 as is shown generally by arrow 52 inFIG. 4A.

In this regard, in the exemplary embodiment shown in FIGS. 4-6, theflexible member 46 extends from the shaft 104 into the cartridge 44 at aproximal end 44 b and ultimately couples the anvil 42 to the cartridge44. While numerous pathways for the flexible member are possible, in theexemplary embodiment, the flexible member 46 passes from the cartridge44 and is coupled to the anvil 42 adjacent each of a distal end 42 a anda proximal end 42 b thereof and may be anchored within the anvil 42 byanchors 110 and 112 (shown in FIG. 6).

Retraction of the flexible member 46 from the end effector 40 (and intothe manipulator 102 described below) therefore moves at least one of theanvil 42 and/or the cartridge 44 as is shown generally by the arrow 52in FIG. 6. It will be appreciated that because the flexible member 46 isanchored to the anvil 42 (e.g., proximate each of the distal end 42 aand the proximal end 42 b), retraction of the flexible member 46produces a substantially symmetrical closing force on tissue situatedbetween the anvil 42 and the cartridge 44. This configuration, that is,with connectivity between the anvil 42 and the cartridge 44 at each endof the end effector 40, is advantageous.

In this regard, in embodiments in which the anvil 42 and/or thecartridge 44 are sufficiently rigid at pressures encountered during asurgical procedure, the clamping force may be more symmetrical anduniformly distributed along the length of the anvil 42 and the cartridge44. Thus, the tissue situated between the anvil 42 and the cartridge 44may be more uniformly compressed. It will be appreciated that eventhough there may be more uniform compression on the tissue, the anvil 42and the cartridge 44 may not be parallel to one another in the clampedposition because the tissue may not be uniformly thick. Nevertheless,there may be uniformity in applied pressure. Alternatively, the anvil 42and the cartridge 44 may be generally parallel yet a gap between theopposing faces of each varies in dimension between a distal end and aproximal end of the end effector 40. The variation in gap may beaccording to a predetermined relationship to accommodate for the changein thickness of the compressed stomach during clamping. Even though thegap may vary in dimension from one end to the other, the end effector 40may uniformly apply pressure to the clamped tissue. In each instance,this may be unlike prior art devices in which clamping members areattached together at a single, hinge-like location and have a jaw-likemotion, rather than a vice-like motion. With a single connection, theend of the clamp member most distant from the connection may deflect. Asa result of the deflection, the clamp member may not apply uniform,symmetrical compression to the tissue along its length. Furthermore,deflection becomes more exaggerated as the clamp members lengthen. Thus,deflection limits the practical upper limit on length for hinge-likedevices. It was recognized that producing a substantially uniformlyapplied clamping pressure may enhance the formation of the staple linefollowing stapling and cutting.

With reference to FIGS. 3, 4, 5, and 6, in one embodiment, themanipulator 102 includes a main body 114 with housing halves 120 a, 120b. When assembled, the housing halves 120 a, 120 b enclose controlfeatures by which the surgeon may operate clamping of the anvil 42 andthe cartridge 44 on the stomach 10 and then stapling and cutting of thestomach 10. In that regard, the manipulator 102 includes a clampingmechanism 122 for applying tension to the flexible member 46, a staplingmechanism 124 for stapling the tissue captured between the anvil 42 andthe cartridge 44, and a cutting mechanism 126 for cutting the tissue.Each of these mechanisms is described below. Thus, in one aspect, thesurgeon may operate the clamping mechanism 122 to control the extensionand retraction of the flexible member 46 from the end effector 40. Inanother aspect, the surgeon may actuate the stapling mechanism 124 tofire staples and actuate the cutting mechanism 126 to cut tissue. Itwill be appreciated that while the endocutter stapling device 100 isdescribed herein as including each of these mechanism, that is, aclamping mechanism, a stapling mechanism, and a cutting mechanism, theinvention is not limited to having a cutting mechanism. Specifically,the endocutter stapling device 100 may include a stapling mechanism andnot include a cutting mechanism. The surgeon may therefore use theendocutter stapling device 100 to clamp and staple the tissue withoutcutting it.

To these and other ends, with continued reference to FIG. 5, themanipulator 102 includes a support 130 having a U-shaped cross-sectioncoupled to the end effector 40 at a proximal end. A guide beam 136 ofabout the same length as the support 130 and reinforces the support 130.The guide beam 136 may include three channels 138 a, 138 b, and 140 thatmay receive portions of each of the stapling mechanism 124, the cuttingmechanism 126, and the clamping mechanism 122, described below.

In the embodiment shown, the manipulator 102 further includes a frame150 having a shaft portion 152 and a handpiece portion 154. The shaftportion 152 may have a tubular configuration, for example, a rightcircular tubular configuration and may enclose the support 130 and theguide beam 136 when the manipulator 102 is assembled. The support 130may be configured to receive a pin 142 that cooperates with acorresponding bore 144 in the shaft portion 152 to secure the support tothe frame 150.

The handpiece portion 154 of the frame 150 is enclosed in the handpiece106 and includes opposing flanges 156 a, 156 b defining a channel 158.Each of the flanges 156 a, 156 b includes one or more slots that guide aportion of the clamping mechanism 122, described below. In theembodiment shown, each flange 156 a, 156 b includes two pairs of slots160 a, 160 b, 162 a, 162 b. The pair of slots 160 a, 162 a on the flange156 a is a mirror image of the pair of slots 160 b, 162 b on the flange156 b. As shown, each of the slots 160 a, 160 b is elongated in adirection generally parallel with the longitudinal axis of themanipulator 102. The slots 162 a, 162 b are also elongated but areangled with respect to the longitudinal axis of manipulator 102 andangled relative to the slots 160 a, 160 b.

The clamping mechanism 122 includes a lever 170 pivotably coupledrelative to the housing halves 120 a, 120 b by the pin 142 in the bore144. The surgeon operates the lever 170 to tension the flexible member46. In particular, with reference to FIGS. 6 and 7, the surgeon maysqueeze the lever 170 by which motion the flexible member 46 iswithdrawn from the end effector 40. As is described above, withdrawingor pulling the flexible member 46 from the end effector 40 draws theanvil 42 toward the cartridge 44 and may tension the flexible member 46when the anvil 42 and the cartridge 44 meet resistance to movement. Byapplying a force to the flexible member 46, the anvil 42 and thecartridge 44 may be moved toward one another (as is indicated by arrow52) and may also apply a clamping force to tissue situated between theanvil 42 and the cartridge 44. It will be appreciated that the surgeonmay operate the lever 170 with one or more fingers during operation ofthe endocutter stapling device 100 between a disengaged position (e.g.,FIGS. 3 and 6) in which the clamping mechanism 122 does not restrictmovement of the flexible member 46 and an engaged position (e.g., FIGS.4 and 7) in which the clamping mechanism 122 contacts the flexiblemember 46.

To that end, the clamping mechanism 122 further includes a push bar 164pivotably coupled to the lever 170 by a pin 166 at one end thereof. Thepush bar 164 extends from outside the housing half 120 a, where it ispivotally attached to the lever 170 by the pin 166, into the channel 158of the frame 150 through a slot (unlabeled) in the handpiece portion 154of the frame 150. The push bar 164 is pivotally coupled to a push bar174 by a pin 172 in the handpiece 106. The pin 172 extends through thepush bar 164 at one end thereof across the channel 158 and is slidablyreceived in each of the slots 160 a, 160 b (FIG. 5) of the frame 150.The push bar 174 is coupled to a second pin 176 at the opposing end ofthe bar 174 from the pin 172. The pin 176 is slidably received in eachof the slots 162 a, 162 b (FIG. 5) of the frame 150. The pins 172 and176 interact with the flexible member 46 when the surgeon squeezes thelever 170. By way of example only, and not limitation, one or both ofthe pins 172 and 176 may be coupled to a sheave (not shown), whichslidably receives the flexible member 46, to guide the flexible member46 during operation of the clamping mechanism 122.

With continued reference to FIG. 6, the flexible member 46 extends fromthe shaft 104, between the flanges 156 a, 156 b, and is looped over thepin 172 and the pin 176 (e.g., in sheaves on each pin 172, 176). In theexemplary embodiment, an additional pin 178 may extend across thechannel 158 in fixed relation to the frame 150. The pin 178 may bepositioned at a location that maintains the flexible member 46 inalignment with the shaft 104. In other words, the pin 178 may beconfigured to align the flexible member 46 with the shaft 104independent of the position of the pins 172, 176 as the pins 172, 176slide in relation to the slots 160 a, 160 b, 162 a, 162 b. Thus, whilethe flexible member 46 may move in response to actuation of the clampingmechanism 122 along each of the pins 172, 176, the additional pin 178may maintain alignment of the flexible member 46 with the longitudinalaxis of the manipulator 102.

With reference to FIGS. 6 and 6A, depression of the clamping lever 170toward the housing half 102 a in the direction of the arrow 180 in FIG.6 may cause movement of each of the push bars 164, 174 generally awayfrom the end effector 40 in the direction of the longitudinal axis ofthe handpiece 106. Specifically, as is shown in FIG. 6, the push bars164, 174 initially have a generally L-shaped arrangement when the lever170 is extended from the handpiece 106. In this disengaged position ofthe lever 170, the anvil 42 is spaced apart from the cartridge 44, as isshown in FIGS. 6 and 6A. As the lever 170 is compressed towards thehandpiece 106 (according to the arrow 180), the push bar 164 pushes thepin 172 along the slots 160 a, 160 b (according to the arrow 184). Thismovement also simultaneously forces the push bar 174 along thelongitudinal axis of the manipulator 102 as guided by the pin 172 in theslots 162 a, 162 b (according to the arrow 186). The pins 172, 176 carrythe flexible member 46 in the same direction away from the end effector40. Overall, the flexible member 46 is withdrawn from the end effector40 resulting in movement of the anvil 42 toward the cartridge 44. Inaccordance with embodiments of the invention, a gap between the anvil 42and the cartridge 44 may vary when the surgeon clamps the stomach 10. Inthis regard, the clamping mechanism may be configured to create a gap atthe distal end 42 a, 44 a of the end effector 40 that is less than thegap at the proximal end 42 b, 44 b of the end effector when the clampingmechanism is engaged. In one embodiment of the invention, the clampingmechanism may be configured to withdraw the flexible member 46 from theend effector 40 such that the length of flexible member between thedistal ends 42 a, 42 b of the anvil 42 and the cartridge 44 is less thanthe length of flexible member 46 between the proximal ends 42 b, 44 b ofthe anvil 42 and the cartridge 44. As is described below, the anvil 42may therefore be intentionally tilted relative to the cartridge 44 suchthat the gap is not uniformly formed between the anvil 42 and thecartridge 44. This gap configuration may then be imposed on the stomach10 though it may produce more uniform pressure distribution on thestomach 10. Those of ordinary skill in the art will recognize that theremay be other configurations resulting in a varying gap between the anviland the cartridge that are useful in embodiments of the presentinvention.

Compression of the lever 170 into the engaged position results in theconfiguration of the endocutter stapling device 100 shown in FIGS. 7 and7A, in which the push bars 164, 174 are generally aligned with respectto one another and the anvil 42 and cartridge 44 are compressed onto thestomach 10. In the generally aligned configuration between the push bars164, 174, the path around which the flexible member 46 extends islengthened relative to the L-shaped arrangement shown in FIG. 6. Bylengthening the path, the flexible member 46 is carried rearwardlywithin the handpiece 106 during actuation of lever 170. This results ina corresponding withdrawal of the flexible member 46 from the endeffector 40. Accordingly, the compression of the lever 170 toward thehousing half 120 a pulls the anvil 42 towards the cartridge 44 as isindicated by arrow 52 in FIG. 7. This motion may result in compressionof the stomach 10 between the anvil 42 and the cartridge 44, as is shownin FIG. 7A. By way of example and not limitation, the clamping mechanism122 may be capable of tensioning the flexible member 46 to about 200 lbat each end of the anvil 42. This may provide a clamping pressure ofover 100 psi. Specifically, in an exemplary embodiment, the anvil 42 andthe cartridge 44 may have a length of about 250 mm and a width of about10 mm providing a surface area of about 25 cm2. With 400 lb of totaltension on the flexible member 46 (i.e., 200 lb on each side), the totalcompression pressure may be about 103 psi.

With reference now to FIG. 6A, in one embodiment, the anvil 42 includesa plurality of staple pockets 190 along a face 192 of the anvil 42. Thecartridge 44 includes a face 194 that opposes the face 192 of the anvil42. Each of the faces 192, 194 is configured to compress the stomach 10there between. The staple pockets 190 in the face 192 generally alignand correspond to a plurality of staples 198 and a plurality of stapledrivers 200 that are housed in a plurality of staple channels 206defined by the cartridge 44. The cartridge 44 includes a cartridge body196 that may support the staples 198 and the staple drivers 200. Thestaples 198 are configured to be forced through the stomach 10 and bedeformed by the staple pockets 190. It will be appreciated thatdeforming the staples 198 into a B-shaped configuration secures opposingsides of the stomach 10 together.

In one embodiment, to facilitate alignment between the anvil 42 and thecartridge 44, and in particular, alignment between the staples 198 andthe staple pockets 190, an alignment pin 202 may extend beyond the face192 at the distal end 42 a of the anvil 42 or the face 194 at the distalend 44 a of the cartridge 44. The other face 192, 194 of the anvil 42 orthe cartridge 44 includes a mating recess 204. Once the lever 170 iscompressed, the flexible member 46 is pulled into the handpiece 106 bythe clamping mechanism 122 as described above. This motion pulls theanvil 42 toward the cartridge 44 and the alignment pin 202 inconjunction with the mating recess 204 to facilitate proper alignmentbetween the anvil 42 and the cartridge 44 to align the staples 198 witha corresponding pocket 190. With reference to FIG. 7A, the anvil 42 andthe cartridge 44 are shown to compress the stomach 10 between the face192 of the anvil 42 and the face 194 of the cartridge 44 with thealignment pin 202 being received in the mating recess 204. In anotheraspect of the present invention, once the lever 170 is compressed, as isshown in FIG. 7, with the anvil 42 and the cartridge 44 compressing thestomach 10 there between, the surgeon may staple and cut the stomach 10along the staple line 12 (FIG. 1). To staple the stomach 10, the surgeonactivates the stapling mechanism 124.

In that regard and with reference to FIGS. 3, 8, and 9, the staplingmechanism 124 includes a staple actuator 210 having a thumb tab 212. Thestaple actuator 210 further includes an actuator plate 214 that iscoupled to the thumb tab 212. The actuator plate 214 is slidablyreceived in a slot 218 (FIG. 3) formed between the housing halves 120 a,120 b and is movable relative to the handpiece 106 as is indicated bythe arrow 232 in FIGS. 8 and 9. The actuator plate 214 includes slots222 a, 222 b spaced apart from an elongated slot 224. In the embodimentshown, the slots 222 a, 222 b each receive a wedge push bar 226 a, 226b, respectively. As is shown in FIGS. 5 and 10, the wedge push bars 226a, 226 b are elongated members that extend generally along the length ofthe handpiece 106 and through the shaft 104 and terminate proximate theend effector 40. The wedge push bars 226 a, 226 b are slidably receivedin corresponding channels 138 a, 138 b of the guide beam 136 and arepositioned to slide into engagement with the staples 198 and the stapledrivers 200 in the cartridge 44.

In one embodiment, shown in FIG. 10, each wedge push bar 226 a, 226 bterminates in a wedge tip 230 a, 230 b which, prior to activation of thestapling mechanism 124, is positioned to engage respective rows of thestaple drivers 200 in the cartridge 44. The wedge tips 230 a, 230 b havea wedge-shaped configuration and, during a sliding motion through theend effector 40, are configured to force the staple drivers 200 towardthe anvil 42 and drive the corresponding staples 198 through thecompressed stomach 10 and into contact with the corresponding staplepockets 190 of the anvil 42. As shown best in FIGS. 10 and 10B, theshape of the wedge tips 230 a, 230 b forces the staples 198 into contactwith the staple pockets 190 of the anvil 42 with sufficient force todeform the staples 198 and produce a B-shaped staple.

In one embodiment, the surgeon activates the stapling mechanism 124 bypushing the thumb tab 212 in the direction of the end effector 40 as isindicated by the arrow 232 in FIGS. 8 and 9. Pushing the thumb tab 212slides each of the wedge push bars 226 a, 226 b and the correspondingwedge tips 230 a, 230 b in the direction of the end effector 40.Specifically, and with reference now to FIGS. 10C-10D, pushing the thumbtab 212 (FIG. 8) moves the wedge push bars 226 a, 226 b in the directionof the arrow 234. The wedge tip 230 a engages the staple drivers 200 insequence and thereby forces the staples 198 into the correspondingstaple pockets 190 on the anvil face 192 as is indicated by the arrows238.

In another aspect of the present invention, the surgeon may cut thestomach 10 along the staple line 12 following stapling, described above.In one embodiment and with reference to FIG. 5, to cut the stomach 10,the surgeon activates the cutting mechanism 126. The cutting mechanism126 includes a knife actuator 248 including the thumb tab 212 coupled tothe actuator plate 214. As described above and with reference to FIGS. 8and 9, the actuator plate 214 is slidably received in the slot 218formed between the housing halves 120 a, 120 b and is movable relativeto the handpiece 106 in a direction that is indicated by the arrow 232in FIGS. 8 and 9.

With reference to FIGS. 10-10A, in one embodiment, the cutting mechanism126 includes the elongated slot 224 in the actuator plate 214. A knifepush bar 250 is slidably engaged in the elongated slot 224 and may be anelongated member extending from the actuator plate 214 through thehandpiece 106 and the shaft 104 to a location adjacent the end effector40. In that regard, the knife push bar 250 is slidably received in thechannel 140 of the guide beam 136 and terminates in a cutting edge 252proximate the end effector 40 (shown best in FIGS. 10-10D). As can beappreciated specifically by FIGS. 5, 10C and 10D, the knife push bar 250lies in between the wedge push bars 226 a, 226 b. In one embodiment, thesurgeon activates the cutting mechanism 126 by pushing the thumb tab 212in the direction of the end effector 40 as is indicated by the arrow 232in FIG. 8. Pushing the thumb tab 212 slides the knife push bar 250 viathe actuator plate 214 and pushes the corresponding cutting edge 252 inthe direction of the end effector 40.

Specifically, and with reference now to FIGS. 10, 10A, and 10B, pushingthe thumb tab 212 moves the cutting edge 252 in the direction of thearrow 254 along the longitudinal axis of the endocutter stapling device100. Although not shown, the cutting edge 252 cuts the stomach that maybe clamped between the anvil 42 and the cartridge 44.

In one embodiment, and with reference to FIGS. 8 and 9, the thumb tab212 may activate each of the stapling mechanism 124 and the cuttingmechanism 126. As is described above, the actuator plate 214 captureseach of the wedge push bars 226 a, 226 b and the knife push bar 250 inslots 222 a, 222 b and elongated slot 224, respectively. In oneembodiment, even though the actuator plate 214 is operably coupled toeach of the wedge push bars 226 a, 226 b and the knife push bar 250,engagement of the stapling mechanism 124 occurs prior to actuation ofthe cutting mechanism 126. In other words, the stapling mechanism 124engages prior to engagement of the cutting mechanism 126. The elongatedslot 224 in the actuator plate 214 is oversized relative to the portionof the knife push bar 250 that is engaged with it. This configurationresults in sliding space between the elongated slot 224 and the knifepush bar 250. The knife push bar 250 therefore slides relative to theactuator plate 214 during initial movement of the actuator plate 214.The length of the movement of the actuator plate 214 without movement ofthe knife push bar 250 is predetermined.

The elongated slot 224 is also longer than each of the slots 222 a, 222b. Because the knife push bar 250 is slidably received in the elongatedslot 224, the initial movement of the actuator plate 214 in thedirection of arrow 232 in FIG. 8 causes each of the wedge push bars 226a, 226 b to move in direct relation to the movement of the actuatorplate 214. The movement of the knife push bar 250 is however delayedrelative to the movement of the wedge push bars 226 a, 226 b. This meansthat there is a delay between activation of the stapling mechanism 124and the cutting mechanism 126. This delay is proportional to the freesliding space between the elongated slot 224 and the knife push bar 250.

When the surgeon pushes the thumb tab 212 in the direction of the arrow232 in FIG. 8, the actuator plate 214 moves in the same direction andcarries the wedge push bars 226 a and 226 b with it. The knife push bar250 does not initially move. Instead, the actuator plate 214 must move apredetermined distance corresponding to the free sliding space in thedirection of the end effector 40 before the actuator plate 214 engagesthe knife push bar 250. This is shown by way of comparison between FIGS.8 and 9. In FIG. 8, the actuator plate 214 has not engaged the knifepush bar 250. In FIG. 9, the actuator plate 214 has moved a distance atleast equivalent to the free sliding space and so the actuator plate 214engages the knife push bar 250. This delay in movement between the wedgepush bars 226 a, 226 b and the knife push bar 250 results in adifference in activation time between the stapling mechanism 124 and thecutting mechanism 126. In this manner, in one embodiment, activation ofthe stapling mechanism 124 precedes activation of the cutting mechanism126.

Once the surgeon activates each of the stapling mechanism 124 and thecutting mechanism 126 by pushing on the thumb tab 212, stapling andcutting may occur substantially simultaneously. By way of example only,the stapling of the stomach 10 may precede the cutting of the stomach10. That is, after an initial delay between stapling and cutting, duringwhich the stapling mechanism 124 is activated, both of the staplingmechanism 124 and the cutting mechanism 126 are active. The surgeon maycontinue stapling and cutting the stomach 10 by continuing to push onthe thumb tab 212 until the thumb tab 212 reaches the end of its stroke.It will be appreciated that the stroke of the thumb tab 212 may begreater than the overall length of the stomach 10. Further, the strokeof the thumb tab 212 may be approximately equal to the length of the endeffector 40. At this point, the wedge tip 230 a, 230 b may be proximatethe distal end 42 a, 44 a of the end effector 40. The end effector 40and the shaft 104 may then be removed from the abdominal cavity with thestomach 10 having the configuration shown in, for example, FIG. 2E.Tensioning, stapling, and cutting mechanisms are further described inthe commonly-owned U.S. Application No. PCT/US15/22904, which is filedconcurrently with the present application and is being incorporated byreference herein in its entirety.

With reference again to FIG. 1, as described above, the stomach 10 mayvary in thickness from the antrum 24 to the fundus 26. Stomach specimensremoved from patients have been analyzed for tissue thickness at threepoints along a resection line—the antrum 24, the fundus 26, and amid-way point between the antrum 24 and the fundus 26 called the body.These values were used to estimate closed staple leg heights at thesethree locations. A closed staple leg height may be estimated based on aknown tissue thickness along the staple line. Closed staple leg heightrefers to the height dimension of a deformed staple. Open staple legheight may be calculated from a closed staple leg height. Open stapleleg height refers to the height dimension of a new staple. Thus, priorto stapling, each staple has an open staple leg height. During stapling,the staple may be forcibly deformed. Ideally, each leg of a staple isdeformed to produce a B-shaped staple in which a tooth, sometimesreferred to as a point, of each leg points in the direction of thecrown. Following stapling, each deformed staple has a closed staple legheight. The average closed staple leg heights were estimated to be about1.8 mm, about 2.4 mm, and about 3.0 mm for the fundus, the body, and theantrum, respectively. The average open staple leg heights werecalculated to be about 3.8 mm, about 4.4 mm, and about 5.0 mm for thefundus, the body, and the antrum, respectively. Not being bound bytheory, it is believed that the tissue thickness provides informationregarding the closed staple leg height at a particular location. Whenall of the specimens and the estimated closed staple leg heights areconsidered, according to an embodiment of the invention, a relationshipbetween the closed staple leg height and the variation in thickness ofthe human stomach along a targeted resection line was determined.

In this regard, an increase in average thickness from the fundus 26 tothe antrum 24 was calculated. The increase was determined to beapproximately linear with a degree of the increase in the averagethickness of the stomach along the resection lines of these stomachspecimens of about 0.382 degrees. As shown in FIG. 2B, the end effector40 extends across the length of the stomach 10. When compressed, a gapbetween the anvil 42 and the cartridge 44 varies in a predeterminedrelationship relative to this change in tissue thickness. Accordingly,aspects of the present invention may utilize predetermined changes ingap dimensions at defined locations between the anvil 42 and thecartridge 44 along a longitudinal axis of the end effector 40.

To that end, in one embodiment and with reference to FIG. 11, an endeffector 360 includes a gap 370 between the anvil 362 and the cartridge364 at a proximal end 366 of the end effector 360 (“proximal gap 370”)and a gap 372 at a distal end 368 of the end effector 360 (“distal gap372”). The proximal gap 370 is different from the distal gap 372.Specifically, the anvil 362 has a face 376 that includes a plurality ofstaple pockets 378, and the cartridge 364 has a face 380 that opposesthe face 376 of the anvil 362. The proximal gap 370 and the distal gap372 are measured between the faces 376 and 380. The orientation betweenthe face 376 and the face 380 may therefore determine the gaps 370 and372. In one embodiment, the proximal gap 370 is larger than the distalgap 372 when the stomach 10 is compressed between the anvil 362 and thecartridge 364. The difference between the gap 370 and the gap 372 may bedetermined based on the anatomy of the stomach 10 described above. Byway of example, and not limitation, the distal gap 372 may range from,for example, about 1.5 mm to about 3.3 mm, and the proximal gap 370 maybe in the range of about 2.0 mm to about 5.0 mm. Further, and withoutlimitation, the angle of increase in the gap from the distal gap 372 tothe proximal gap 370 may be from about 0.1° to about 1°.

Furthermore, the orientation between the anvil 362 and the cartridge 364may determine all of the distances between the two faces 376, 380 fromthe proximal end 366 to the distal end 368. For example, with continuedreference to FIG. 11, the face 376 of the anvil 362 may not be parallelwith the face 380 of the cartridge 364. As shown, the face 376 may beuniformly sloped at an angle a relative to the face 380 of the cartridge364. The distances between the face 376 and the face 380 may linearlydecrease from the proximal gap 370 to the distal gap 372 according tothe angle a. The angle a may be proportional to a corresponding changein the average closed staple leg heights according to a correspondinglocation along the staple line 12 on the stomach 10. That is, in oneembodiment, the angle a may be directly related to a measured angleacross the average closed staple leg heights by location on the stomach.By way of example only, and not limitation, the distal gap 372 may beabout 1.7 mm, the proximal gap 374 may be about 3.3 mm, and the angle amay be about 0.367 degrees.

As is shown in FIG. 11 and is described in more detail below, thecartridge 364 houses staples 198 and staple drivers 200. Further, thecartridge 364 may be divided into zones in which the staples 198 differin open leg length. The open leg length of the staples 198 may vary inaccordance with the thickness of the stomach 10 when compressed. Itshould be recognized that these values are merely exemplary and theparticular values for the distal and proximal gaps may depend on severalfactors, including the anatomical structure being clamped as well asother factors. Thus, the invention is not limited to the range of valuesprovided herein. Various aspects of the present invention address thevarying gap between the anvil and the cartridge to improve the qualityand consistency of the staple line.

It will be recognized that the varying gap between the anvil and thecartridge along the length of the end effector may affect a delta gap ofthe formed staples. The delta gap is the difference in the gap betweenthe leading leg and the staple crown and the gap between the lagging legand the staple crown. In this regard, an end effector with a gap havingan angle of about 0.382 degrees and including staples with a crownlength of 2.65 mm, may produce a delta gap of about 0.0177 mm. This doesnot exceed known exemplary delta gaps in staples formed using openlinear staplers such as 0.21 mm and 0.29 mm.

In an alternative configuration in which like reference numerals referto like features throughout the figures, and with reference to FIGS.12A-12C, in one embodiment, an end effector 400 includes an anvil 402and a cartridge 404. The anvil 402 has a face 406, and the cartridge 404has a face 408. As shown, a shim 410 is coupled to each of the anvil 402and the cartridge 404. Each shim 410 increases in thickness from theproximal end 366 to the distal end 368 of the anvil 402. An exemplaryshim is shown in FIG. 13. A shim 410 maybe formed from material that isbio-absorbable. The material may also be flexible, and, if it is apolymer, the material may be such that it will not cross link further tobecome a rigid structure. By way of example, and not limitation, theshim material may include dilactones, bioresorbable elastomer made frompoly(glycerol sebacate), polylactide (PLA), polyglycolide (PGA), acopolymer of E-caprolactone and glycolide, or a non-absorbable polymersuch as polytetrafluoroethylene (PTFE). The shim material may alsoinclude biologic materials such as bovine pericardium, small intestinalsubmucosa laminate, or acellular dermal matrix.

The change in thickness of each shim 410 may be determined based on thechange in thickness of the stomach 10, described above. By way ofexample, the thickness of each shim 410 at predetermined locations alongthe length of the shim 410 may be determined at least in part using theestimated thickness of the stomach 10 and the gap between the face 406of the anvil 402 and the face 408 of the cartridge 404 at a givenlocation along the length of the stomach 10 when the faces 406 and 408are substantially parallel. By way of example, the thickness of eachshim 410 may be about one half of the difference in height between thegap and the thickness of the stomach 10 (when compressed) at eachlocation between the faces 406 and 408. With this configuration, theshims 410 compensate for the expected variation in the compressedstomach thickness. When the stomach 10 is compressed between the anvil402 and the cartridge 404, the change in thickness of the shims 410 andthe corresponding change in thickness of the stomach 10 provide agenerally overall consistent total gap between the faces 406 and 408over the length of the end effector 400.

With reference to FIGS. 12B and 12C, during actuation of the endeffector 400, as the wedges 230 a, 230 b push the staple drivers (notshown) toward the anvil 402, the staples 198 pierce through each of theshims 410 at the faces 406, 408 and come into contact with the staplepockets (not shown). As is shown, once the staple line is complete, thestaples 198 having the same open leg length (as is shown in FIG. 12A)will also have generally the same closed leg length along the length ofthe staple line. Advantageously, using the shims 410 may reduce thelikelihood of improper staple formation due to the variable thickness ofthe stomach 10 since the gap between the faces 406 and 408 issubstantially uniform from the proximal end 366 to the distal end 368.Additionally, the presence of the shims 410 may act as reinforcement tothe staple line 12, as can be appreciated from FIG. 12C in which theshims 410 form part of the staple line 12. Further, because each of thestaples 198 has the same open leg length along the entire staple line12, the surgeon is not required to estimate the stomach thickness todetermine what staple open leg length should be placed in the cartridge404. Aspects of the present invention are not limited to the illustratedarrangement, where both the anvil 402 and the cartridge 404 include ashim 410. In one embodiment, for example, the cartridge 404 may becoupled to a shim, while the anvil 402 is not coupled to a shim. Otheralternative arrangements may also be possible.

In one embodiment and with reference to FIG. 14A, a shim 412 may extendalong a part of the length of the anvil 402 and/or along a part of thelength of the cartridge 404. In FIG. 14A, one shim 412 extends fromabout the midway point of the anvil 402 to the distal end 402 a of theanvil 402 and another shim 412 extends from about the midway point ofthe cartridge 404 to the distal end 404 a the cartridge 404. In thisregard, the shims 412 are located adjacent the thinner portion of thestomach 10 and are generally thinner and shorter than the correspondingshims 410 shown in FIG. 12A-12C.

During actuation, some of the staples 198 pass only through the stomach10 from the cartridge 404 to the anvil 402, while other staples 198 willpass through the shims 412 and the stomach 10 before reaching the staplepockets (not shown). Once the staple line 12 is complete, the staples198 having the same open leg length will also have generally the sameclosed leg length along the length of the stomach 10, as is shown inFIG. 14B. In other words, the varying thickness of the shims 412 and thevarying thickness of the stomach 10 combine to provide a generally equalthickness along the length of the staple line. Those of ordinary skillin the art will recognize that aspects of the present invention are notlimited to the illustrated arrangement, in which the shims 412 extendsover generally half of the length of the anvil 402 and cartridge 404.

With reference to FIG. 15A, in one embodiment, an end effector 420includes an anvil 422 and a cartridge 424 where a gap between the anvil422 and the cartridge 424 increases in a stepped configuration fromdistal ends 422 a, 424 a to proximal ends 422 b, 424 b. In the exemplaryembodiment, the face 428 of the cartridge 424 includes segments 430,432, and 434. Each segment 430, 432, 434 resides in a plane that differsfrom planes for each of the other segments 430, 432, 434 to producethree different gap dimensions with the face 426 of the anvil 422. Thedifferent gap dimensions may be related to the difference in thicknessof the stomach 10 along the staple line 12, as is described above. Asshown, the staples 198 in each segment 430, 432, 434 may have the sameopen leg length. To accommodate for the difference in height in eachsegment 430, 432, 434, the staple drivers 200 vary in height by segment430, 432, 434. Thus, as the wedge (not shown) forces the staple drivers200 toward the anvil 422, the staples 198 will be fully pushed out ofthe staple channels. While three segments 430, 432, 434 are shown, itwill be appreciated that the face 428 of the cartridge 424 may bedefined by at least two segments and may be defined by more than threesegments. It should be appreciated that there may be otherconfigurations that allow for the staples 198 to pass through the staplechannels of varying height.

Once the end effector 420 has been fully actuated, the staples 198within each individual segment 430, 432, 434 will generally have thesame open leg length, as shown in FIG. 15B, but differ in closed leglengths compared to each of the adjacent segments 430, 432, 434 due tothe stepped configuration of the gap between the anvil 422 and thecartridge 424. By way of example only, the staples 198 near the proximalend of the staple line 12 will have a greater closed leg length than thestaples 198 near the distal end of the staple line 12. In anadvantageous aspect of the present invention, the stepped configurationof the cartridge 424 aids in providing a consistent staple deformationby taking into account the varying thickness of the stomach 10. Further,the surgeon is not required to determine what size staples to use basedon the expected thickness of the stomach 10.

It should be realized that aspects of the present invention are notlimited to the illustrated arrangements in FIGS. 15A-15B. For instance,the face of the anvil may include a stepped configuration similar tothat of the cartridge 424 shown in FIG. 15A and provide a similar tiereddifference in gap between opposing faces of the anvil and the cartridge.By way of example, with reference to FIGS. 16A and 16B, in which likereference numerals refer to like features of FIGS. 15A and 15B, an endeffector 440 includes an anvil 442 and a cartridge 444 where a gapbetween the anvil 442 and the cartridge 444 increases in a steppedconfiguration from the distal ends 442 a, 444 a to the proximal ends 442b, 444 b. In the exemplary embodiment, the face 426 of the anvil 442includes segments 450, 452, and 454. Each segment 450, 452, 454 residesin a plane that differs from planes for each of the other segments 450,452, 454 to produce three different gap dimensions with the face 428 ofthe cartridge 444. The different gap dimensions may be related to thedifference in thickness of the stomach 10 along the staple line 12, asis described above. As shown, the staples 198 in each segment 450, 452,454 may have the same open leg length. Since there is no heightdifference in the cartridge 444, the staple drivers 200 also have thesame height in each segment 450, 452, 454. Thus, as the wedge (notshown) forces the staple drivers 200 toward the anvil 422, the staples198 will be fully pushed out of the staple channels. While threesegments 450, 452, 454 are shown, it will be appreciated that the face426 of the anvil 442 may be defined by at least two segments or may bedefined by more than three segments.

While each staple 198 within each segment 430, 432, 434 as is shown inFIG. 15A and each staple 198 within each segment 450, 452, 454 as isshown in FIG. 16A, has an equivalent open leg length, embodiments of thepresent invention are not limited to embodiments in which each staple198 has an equivalent open leg length. With reference to FIGS. 17A and17B, in which like reference refer to like features throughout thefigures. In an exemplary embodiment, the end effector 420 cartridge 424includes four segments 430, 432, 434, 436 where the open leg lengths ofthe staples 198 in each segment differ. The open leg lengths of staplesvary among manufacturers. For instance, blue, gold, green, and blackcolors may be used to indicate staple having open leg lengths of 3.5 mm,3.8 mm, 4.1 mm, and 4.4 mm, respectively. By way of example only, andnot limitation, the segments 430, 432, 434, 436 may include black,green, gold, and blue staples, respectively. While the staples 198within each segment 430, 432, 434, 436 are shown as having the same openleg length, it will be appreciated that the open leg lengths of thestaples 198 within each segment 430, 432, 434, 436 may be different, asis described below. The segments 430, 432, 434, 436 may differ inrelative proportion and so embodiments of the present invention are notlimited to each segment 430, 432, 434, 436 having the same relativelength. As a result, the number of staples 198 in each segment 430, 432,434, 436 may be different.

As is described above with respect to FIG. 11, in one embodiment, theproximal gap 370 and the distal gap 372 may be different and the face376 of the anvil 362 may be oriented at an angle a with respect to theface 380 of the anvil 362. Where the gap between the distal end 368 andthe proximal end 366 increases linearly, the angle a between the face376 of the anvil 362 and the face 380 of the cartridge 364 may bedetermined. In a similar configuration and with reference to FIG. 18,the end effector 360 may include zones of staples 198, with one or morezones having staples 198 of different open leg lengths. The angle a maybe used to determine the incremental increase in the gap between theanvil 362 and the cartridge 364 for the purpose of selecting differentstaples 198 for the zone. Based on this incremental increase, thecartridge 364 may be divided into, for example, zones 1, 2, and 3, asshown. The dimensions of each zone 1, 2, and 3 may be determinedaccording to a minimum closed leg length necessary to adequately staplethe tissue in that zone. And, the staples 198 in each zone may have anopen leg length that exceeds a minimum open leg length necessary toprovide the minimum closed leg length within that zone.

Determining the minimum closed leg length according to zones allows fora determination of the appropriate open leg length for the staples 198in the respective zone. With reference to FIG. 19, and by way ofexample, and not limitation, the distal gap may be about 1.7 mm, and theproximal gap may be about 3.3 mm. The angle a may be approximately 0.367degrees. This information may be used to calculate zones of differentopen leg lengths. The number and length of each zone may be varied basedon the proximal gap and distal gap of the end effector 360. In FIG. 19,the cartridge 364 includes three zones of, for example, blue (3.5 mm),gold (3.8 mm), and green (4.1 mm) open staple leg lengths from thedistal end to the proximal end. Embodiments of the present invention arenot limited to the illustrated arrangement, where the cartridge 364includes four zones of staples 198 having different open leg lengths.Other alternative arrangements may also be possible.

In one embodiment, and with reference to FIGS. 20A-20C, using theexemplary color-coded open staple leg lengths, the zones 1, 2, 3, and 4of the cartridge 364 may use blue (3.5 mm), gold (3.8 mm), green (4.1mm), and black (4.4 mm) staples, respectively. Each color is associatedwith a specific open leg length. After completion of the staple line,the staples 198 within each zone 1, 2, 3, and 4 may have approximatelythe same closed leg length, as shown in FIG. 20C.

According to one aspect of the present invention and with reference toFIG. 21, in one embodiment, the cartridge 364 may be randomly loadedwith staples 198 having different open leg lengths. In this manner, arandom fill of the cartridge 364 may be advantageous in that it“automatically” adjusts for the variation in tissue thickness along thelength of the staple line 12. That is, within the random staples 198 itis likely that one or more will exceed the minimum open leg lengthnecessary to provide the necessary closed leg length. After the stapleline 12 is complete, the closed leg lengths of the staples 198 will varydepending on the open leg length and the gap between the cartridge 364and the anvil (not shown). Randomly filling the cartridge 364 withstaples 198 of different sizes is an improvement over conventionalstaplers where the surgeon is required to determine what size staples198 should be used because at least a portion of the staples 198 in therandom fill are likely to be the appropriate length.

In one embodiment, the changing thickness of the stomach may be used inpart to determine what minimum open leg length to use in each zone of acartridge. A random selection of different staples may be made withrespect to that minimum. That is, a distribution of staples of differentopen leg lengths may be selected with staples having open leg lengthsabove and below the minimum open leg length. With reference to FIG. 22,in one embodiment, the staples 198 having different open leg lengths maybe placed within the cartridge 364 according to a probability based onthe average stomach thickness at that location. This is similar to thezones described above but with staples having different open leg lengthswithin a particular zone. Within each zone, the staples 198 may berandomly filled. Further in this regard, the change in the gap betweenthe cartridge 364 and the anvil (not shown) may be calculated along thelength of the cartridge 364 and may be utilized to further improve theprobability determination on a zone by zone basis. As is shown in FIG.22, staples 198 having a larger open leg length may be used morefrequently near the antrum or near the proximal end 366 of the cartridge364, and staples 198 having a shorter open leg height may be used morefrequently near the fundus or near the distal end 368 of the cartridge364.

In one embodiment using these exemplary staples, staples 198 in one ormore zones of the cartridge 364 adjacent the antrum 24 may include about70% black staples, about 20% green staples, and about 10% blue staples.Staples 198 in one or more zones of the cartridge 364 adjacent thefundus 26 may include about 90% blue staples and about 10% greenstaples. Finally, staples 198 in one or more zones of the cartridge 364between the antrum 24 and the fundus 26 may include about 33% blackstaples, about 33% green staples, and about 33% blue staples. Includingstaples 198 having varying open leg lengths based on a determinedprobability of the tissue thickness advantageously provides an improvedlikelihood that one or more staples 198 are appropriately sized withinany given zone based on the varying tissue thickness of the stomach 10.

With reference to FIGS. 23 and 23A-23C, in one embodiment, in which likereference numerals refer to like features throughout the figures, thecartridge 364 includes one or more zones of staples 198 in which theopen leg lengths of the staples 198 change according to a particularpattern in one or more directions. That is, the staples 198 are notrandomly distributed, as described above. Rather, the staples 198 arearranged in a predetermined, organized pattern. By way of example, thestaples 198 may be arranged to change size in a direction perpendicularto the longitudinal axis of the cartridge 364, referred to as columns,and/or in a direction parallel to the longitudinal axis of the cartridge364, referred to as rows. FIG. 23 depicts a single row of staples 198that may be divided into zones 1 and 2 of staples 198. Each zone 1 and 2may have a single predetermined open leg length of staple 198, as shown.The predetermined pattern of the staples 198 having different open leglengths along the rows and/or columns of the cartridge 364 may bedetermined based upon the expected closed leg length in each zone, as isdescribed above.

With reference to FIGS. 23A and 23B, the cartridge 364 may include fourrows I, II, III, and IV of staples 198. Each row of staples 198 withineach zone may be of different open leg length and/or gauge. For example,column A, shown in FIG. 23A, may include staples 198 of a differentgauge than the staples 198 in column B, shown in FIG. 23B, though theopen leg length of the staples 198 in the corresponding rows of eachcolumn may be the same. Taking each of the rows and columns shown inFIGS. 23-23B into account, each zone with the corresponding rows andcolumns may be shown in FIG. 23C. Zones 1 and 2 include staples 198 ofdifferent open leg lengths. Zones 1 and 2 also differ in the wirediameter, or gauge, of the staples 198. By way of example, and withcontinued reference to FIG. 23C, zone 1 may include rows I, II, and IIIof staples 198 having open leg lengths of 4 mm, 4.5 mm, and 5 mm,respectively, in each column. Zone 2 may include rows I, II, and III ofstaples 198 having open leg lengths of 3 mm, 3.5 mm, and 4 mm,respectively. The staples 198 of row IV is on the to-be-excised portionof stomach 10 and is shown in phantom. The number and length of thezones will vary based on the proximal and distal gaps of the endeffector as is described above. Thus, it should be realized that aspectsof the present invention are not limited to the illustrated arrangement,where the cartridge 364 includes two zones of rows and columns havingstaples 198 of different open leg lengths and/or different gauges. Otheralternative arrangements may also be possible.

With reference to FIG. 24A, in one embodiment, a cartridge 460 may beconfigured to include a plurality of magazines 462 that may be separatedand reassembled. Each magazine 462 may include three rows 464 of staples198 and be assembled to define a channel 468 for a cutting knife (notshown). The stomach 10 is often stapled on both sides of the cuttingblade to prevent the release of undesirable contents of the excisedportion of the stomach into the abdominal cavity. While the rows 464 oneach side of the channel 468 are specifically shown to mirror oneanother, it would be readily appreciated that, in alternate embodiments,the rows 464 of staples 198 on the side of the stomach that will beexcised (anatomical left) need not mirror the rows of staples on theside of the resultant stomach pouch (anatomical right).

With reference to FIGS. 24A, 24B, and 24C, the magazines 462 may have aninterlocking feature 470 that, in the exemplary embodiment shown,includes a projection 472 that extends outwardly from a main body 474 ofthe magazine 462 and a recess 476 that extends into the main body 474 ofthe magazine 462. When the magazines 462 are assembled, the adjacentmagazines 462 engage each other through abutting contact. Moreparticularly, the projection 472 is positioned within the recess 476 tocouple adjacent magazines 462 back-to-back. The interlock betweenadjacent magazines 462 may more firmly stabilize the cartridge 460during use but allow the surgeon to adjust the overall length of thecartridge 460. The interlocking feature 470 may also more easily allowfor the rows 464 to be positioned with the staples 198 staggered fromeach adjacent row. By way of example, without limitation, the magazine462 may be from about 5 mm to about 260 mm in length. In one embodiment,the magazine 462 may be, for example, about 60 mm in length. In thiscase, four magazines 462 may be used to prepare one staple line. Eachmagazine 462 may include staples 198 having open leg lengths differentfrom the staples 198 in an adjacent or another magazine 462. Otheralternative arrangements may also be possible.

The surgeon may determine which magazine 462 to use based on theincluded open staple leg lengths and the thickness of the stomach asdescribed above. Further, the magazines 462 may vary in height, as shownin FIGS. 24B and 24C with one or more of the heights H1, H2, and H3 ofthe magazines 462 differing from one another. In this regard, the gapbetween the cartridge 460 and the anvil (not shown) may vary along thelength of the cartridge 460 in a staggered configuration by eachmagazine 462. In one embodiment, four magazines 462 from the proximalend to the distal end may include staples 198 having an open leg lengthof 4.4 mm (black), 4.1 mm (green), 3.8 mm (gold), and 3.5 mm (blue),respectively. When these magazines 462 are placed into the cartridge 460and the stomach 10 is compressed between the anvil (not shown) and thecartridge 460, the gap at each of the four magazines may be 2.3 mm, 2.0mm, 1.8 mm, and 1.5 mm, respectively. In this regard, the surgeon mayadvantageously adapt the cartridge 460 depending on the anatomy of theindividual patient. Those of ordinary skill in the art will recognizethat there may be other configurations of magazines 462 useful inembodiments of the present invention.

With reference to FIGS. 25 and 26A and 26B, in one embodiment, acartridge 480 includes a plurality of magazines 482 that may beelongated as compared to the magazines 462 described above withreference to FIGS. 24A-24C. In one embodiment, each magazine 462 mayextend from the proximal end to the distal end of the cartridge 480.Each magazine 482 may include one or more rows of staples 198 inmultiple columns. In the exemplary embodiment shown, a separate magazine482 defines each of rows I, II, III, and IV with row IV having twostaggered columns of staples 198. As with the magazines 462 above, eachmagazine 482 may include staples 198 having different open leg lengthsand/or gauges from the staples 198 in adjacent magazines 462. Further,the magazines 462 may vary in height. In this regard, the gap betweenthe cartridge 480 and the anvil (not shown) may vary in the transversedirection, as shown by comparison of FIGS. 27A and 27B. The magazines482 may be, for example, about 250 mm in length. The surgeon maydetermine which magazines 482 to use based on the included open stapleleg lengths and personal preferences regarding the completed stapleline. In one embodiment, the surgeon may choose staples 198 having alarger open leg length adjacent an outer edge 486 of the cartridge 480and staples 198 having a smaller open leg length adjacent a knifechannel 488 in the cartridge 480. In this regard, the surgeon mayadvantageously adapt the cartridge 480 depending on the anatomy of theindividual patient.

With reference to FIGS. 27A-27C in which like reference numerals referto like features throughout the figures, in one embodiment, a shim 490is coupled to each of the anvil 42 and the cartridge 44. The shims 490increase in thickness from the first edges 492, 494 to the second edges496, 498 of the anvil 42 and the cartridge 44. When the stomach 10 iscompressed between the anvil 42 and the cartridge 44, the predeterminedthickness of the shims 490 provides different levels of compressionacross the width of the staple line 12, as is shown in FIG. 27B. Inother words, the portion of the shims 490 with a greater thicknessprovides more compression. During actuation of the wedge (not shown),the staple drivers 200 are forced toward the anvil 42, the staples 198pierce through the shims 490 coupled to each of the anvil 42 and thecartridge 44 to come into contact with the staple pockets 190.

Once the stomach 10 has been stapled, the staples 198 having the sameopen leg length will also have generally the same closed leg lengthalong the width of the staple line 12 even though the thickness of thestomach gradually decreases toward the edge of the staple line 12. Theincreased compression along the edge of the resultant stomach pouch aidsin providing hemostasis and reducing the possibility of dehiscence.Embodiments of the present invention are not limited to the illustratedarrangement, where both the anvil 42 and the cartridge 44 include a shim490. In an alternative embodiment, for example, the shim 490 may becoupled to the anvil 42, while the cartridge 44 does not include a shim.Furthermore, the configuration of the shim 490 may be used inconjunction with the shim 410 show in FIGS. 13 and 14A. As a result, thethickness of the shims may change in a direction along the longitudinalaxis of the end effector (see e.g., FIG. 13) and may also change in adirection perpendicular to the longitudinal axis of the end effector(see e.g., FIG. 27A).

With reference to FIGS. 28A and 28B, in which like reference numeralsrefers to like features throughout the figures, in one embodiment, ashim 500 is positioned on the face 194 of the cartridge 44 adjacent theknife channel 488 over selected rows I and II of staples 198. A secondshim 502 is coupled to the face 192 of the anvil 42 and a location thatopposes the first shim 500 on the face 194 of the cartridge 44. Once thestomach 10 has been stapled, the shims 500, 502 may form a portion ofthe staple line 12 and provide a localized increase in compressionacross a selected width of the tissue in the staple line 12, as isillustrated in FIG. 28B. Alternative arrangements may also be possible.

With reference to FIGS. 29 and 30A, in which like reference numeralsrefer to like features throughout the figures, in one embodiment, thecartridge 44 includes rows I, II, III, V, VI, and VII of staples 198.The staples 198 in one or more of the rows I, II, III, and IV may havedifferent crown lengths, different leg lengths, and/or different wirediameters. In the exemplary embodiment shown, rows I and II may includestaples 198 having a shorter leg length than the staples 198 in rows IIIand VI, as shown in FIG. 30A. Additionally, the staples 198 in rows Iand II may have a smaller wire diameter, or gauge, than the wirediameter of the staples 198 in rows III and VI. In this regard, thestaples 198 in rows III and VI may provide relatively more mechanicalstrength to the staple line 12 and the staples 198 and rows I and II.Instead, the staples 198 of rows I and II may provide improvedhemostasis compared to the staples 198 in rows III and VI. As discussedabove, the rows of staples on the to-be-excised side of the stomach 10need not match or be similar to the rows of staples 198 on the side ofthe resultant stomach pouch. For example, rows V and VII may includestaples 198 having a similar crown length as the staples 198 in rows IIIand VI. In one embodiment, the crown length and wire diameter of thestaples 198 in each of the rows I, II, III, V, VI, and VII may varyalong the length of the cartridge 44 as described above.

With reference to FIGS. 30B and 30C, in which like reference numeralsrefer to like features throughout the figures, in one embodiment, theend effector 40 includes an anvil 510 and a cartridge 512. The anvil 510has an anvil face 514, and the cartridge 512 has a face 516, whichopposes the face 514 of the anvil 510. As shown, the face 514 as anirregular configuration that does not mirror the planar surface definedby the face 516 of the cartridge 512. In the configuration shown, theanvil 510 has a cross-sectional configuration in which the face 514 isgenerally V-shaped. In this regard, the face 514 may include two slopedportions 518 and 520 that intersect the knife channel 488 in the anvil510. The gap between the anvil 510 and the cartridge 512 varies side toside, that is, between the sloped portion 518 and the face 516 andbetween the sloped portion 520 and the face 516. In the embodimentshown, each row of staples 198 in the cartridge 512 includes staples 198having the same open leg length. By way of example only, the gap isgreater at the outside edges of the anvil 510 and the cartridge 512 thanthe gap adjacent edges of the knife channel 488. Due to the angle of thesloped portions 518 and 520, the staple pockets 190 will be separated bydifferent distances as compared to an anvil face that is parallel to theface of a cartridge (for example, as shown in FIG. 6A). Further, thespacing of the staple pockets 190 between the sloped portion 518 maydiffer from the spacing of the staple pockets 190 of the sloped portion520. More specifically, the angle of the sloped portion 518 relative tothe cartridge 512 may be used to determine the location of each staplepocket 190 in the slope portion 518. The same determination may be madewith respect to the sloped portion 520. By way of example only, and notlimitation, the anvil 510 may be about 2.5 mm wide and may be spacedabout 1.0 mm from the cartridge 512 adjacent the knife channel 488 andabout 1.4 mm at the edge of the anvil 510. In this embodiment, the angleof the sloped portions 518 and 520 may each be about 10.8 degrees offparallel with respect to the face 516. Where the cartridge 512 has rowsI, II, and III of staples 198 that are spaced about 1.25 mm apart, thecorresponding rows of pockets 190 in the sloped portion 518 may bespaced about 1.27 mm apart from the row II and may be spaced 2.55 mmapart from the row III.

During activation of the end effector 40, the wedges (not shown) pushthe staple drivers 200 and the staples 198 toward the anvil 510. Wherethe same wedge (not shown) forces the staples 198 toward the anvil 510,the staples 198 in row I contact the staple pockets 190 before thestaples 198 in rows II and III because of the shorter distance to thesloped portion 518 proximate row I. The staples 198 in row II contactthe staple pockets 190 in the face 514 before the staples 198 in row IIIfor the same reason.

Once the stomach 10 has been stapled, the staples 198 having the sameopen leg length may have different closed leg lengths along the width ofthe staple line, as is illustrated in FIG. 30C. In this regard, thestaples 198 in row I may have a smaller closed leg length compared tothe staples 198 in rows II and III. Similarly, the staples 198 in rowIII may have a larger closed leg length than the staples 198 in rows Iand II. In this configuration, the compression provided by the endeffector 40 and difference in closed leg length of the staples 198across the width of the staple line 12 may improve the integrity of thestaple line 12.

In the exemplary embodiment shown in FIG. 31, in which like referencenumerals refer to like features throughout the figures, an end effector570 includes an anvil 572, a cartridge 574, and an alignment mechanism576 that aids in alignment of the anvil 572 with the cartridge 574 andfurther aids in providing uniform compression of the tissue between theanvil 572 and the cartridge 574. A guide slot 578 extends through thecartridge 574 and opens to the cartridge face 194. A guide channel 580extends axially through the cartridge 574. The guide slot 578 opens tothe guide channel 580. The anvil 572 includes a guide slot 582 thatopens to an anvil guide channel 584 and opens to the face 192.

In one embodiment, the alignment mechanism 576 includes a knife 590 thathas an I-shaped cross sectional configuration, much like an I-beam. Theknife 590 has a top flange 592, a bottom flange 594, and a web 596connecting the top flange 592 to the bottom flange 594. The top flange592 slidably engages the guide channel 580 of the anvil 572 and thebottom flange 594 slidably engages the guide channel 580 of thecartridge 574. This configuration improves the rigidity of the endeffector 570 during stapling/cutting. The I-beam configuration maysubstantially prevent any torque produced by the stapling/cutting actionfrom twisting the anvil 572 relative to the cartridge 574 as can beappreciated by the cross-section shown in FIG. 31 in which the knife 590is shown to positively lock the anvil 572 relative to the cartridge 574and thereby prevent their separation and relative side-to-side motionduring cutting/stapling. Other configurations are possible.

In an alternate embodiment, and with reference to FIG. 32, the knife 590may have a Y-shaped top flange 600. In this embodiment where the anvilface 192 is not parallel to the cartridge face 194 in the transversedirection, the Y-shaped top flange 600 may provide improved alignmentwithin a complimentarily shaped guide channel 584. Alignment mechanismsare further described further described in the commonly-owned U.S.Application No. PCT/US15/22904, which is filed concurrently with thepresent application and is incorporated by reference herein in itsentirety.

When the anatomical structure is being compressed by the anvil and thecartridge, the compression should be great enough to stop the flow ofblood to the area to be stapled and/or cut. At the same time, theanatomical structure should be compressed to create a desired gapbetween the anvil and the cartridge to achieve a B-shaped stapleconfiguration along the staple line 12. Once a staple is formed in theB-shaped configuration, the configuration resists changes to the formedheight. Accordingly, it is important to provide sufficient compressionalong the length of the end effector, which becomes more challenging asthe length of the end effector increases. Conventional end effectors donot address the issue of providing sufficient compression along an endeffector where the tissue thickness varies over the length of theanatomical structure being stapled while also providing the desired gapfor achieving a B-shaped staple.

In one embodiment, and with reference now to FIGS. 33-36, the changinggap between the anvil and the cartridge, as is described above in forexample FIG. 11, may affect the track defined by the guide channels 580and 584 of the alignment mechanism 576. In an aspect of the presentinvention, adjusting the configuration of the anvil face and/or thecartridge face to compensate for the decrease in tissue thickness fromthe antrum 24 to the fundus 26 may allow for uniform compression andB-shaped staple formation along the length of the end effector. In FIG.33, the cartridge face 194 is not parallel to the anvil face 192.However, the guide channel 584 is parallel to the anvil face 192. Theorientation of the guide channel 580 may be angled to extend through thecartridge 574 at an angle that is nearly equivalent to but oppositelyoriented from the angle between the cartridge face 194 and the anvilface 192. With this configuration, the track of the knife 590 is thesame along the end effector 570. The gap between the anvil 572 and thecartridge 574 changes as described above with reference to FIG. 11. Inthis regard, the angled cartridge face 194 may compensate for the angledthickness of the stomach 10 while sufficient compression and B-shapedstaple formation is maintained along the length of the end effector 570.The cartridge 574 may be a unitary body, the angled cartridge face 194being an integral part of the unitary body. Alternatively, a separateelement (e.g., a shim) may be coupled to the cartridge 574 to result inthe angled configuration.

In one embodiment, and with reference to FIG. 34, in which likereference numerals refer to like elements throughout the figures, theanvil face 192 is angled relative to the cartridge face 194, while theguide channel 584 of the anvil 572 is generally parallel to thecartridge face 194. As shown, the guide channel 584 is oriented at anangle relative to the anvil face 192 so that the track for the knife 590is constant. In this regard, the angled anvil face 192 may compensatefor the angled thickness of the stomach 10 while sufficient compressionis maintained along the length of the end effector 570. The anvil 572may be a unitary body, the angled anvil face 192 being an integral partof the unitary body. Alternatively, a separate element (e.g., a shim)may be coupled to the anvil 572 to result in the angled configuration.

In one embodiment, and with reference to FIG. 35, in which likereference numerals refer to like elements throughout the figures, theguide channels 580 and 584 are parallel to each other but are eachangled relative to the faces 192, 194. In FIG. 36, the cartridge face194 includes a stepped configuration similar to the shown in, forexample, FIG. 15A. The guide channels 580 and 584 are parallel to oneanother. In this regard, the stepped configuration of the cartridge face194 may compensate for the angled thickness of the stomach 10 whilesufficient compression and B-shaped staple formation is maintained alongthe length of the end effector 570. The cartridge 574 may be a unitarybody, the stepped cartridge face 194 being an integral part of theunitary body. Alternatively, a separate element (e.g., a shim) may becoupled to the cartridge 574 to result in the stepped configuration.

FIGS. 37A-40B each illustrate shapes of staples 198 and shapes of staplepockets 190. In FIGS. 37A and 37B, a B-shaped staple is shown. To shapethe staples 198 into a conventional B shape, the tips of the staple legsmay be bent past the crown. It will be appreciated that this shape mayresult from deformation caused by forcing a staple 198 into the staplepockets 190 shown in FIGS. 39A and 39B. Staple pockets include pairedstaple leg receiving cups that are mirror images in the anvil face. InFIGS. 38A and 38B, a “2-D”-shaped staple 198 is shown. This 2-Dconfiguration may be advantageous where staples 198 having the same openleg length are configured to have different closed leg lengths. Thisconfiguration may be produced with the staple pocket 190 shown in FIGS.40A and 40B. If the tips of the staple legs are bent so that they extendpast the crown, there is a possibility the tips may snag or puncturetissue near the stomach. To prevent this, the staple pockets 190 can beconfigured to allow for the arc segment of the bent staple legs to havea wider radius. More specifically, the longitudinal portion of thestaple pockets 190 is created by two intersecting arcs. The first archas a radius of about 0.040 inch to about 0.060 inch that is cut to adepth of 0.010 inch to 0.030 inch. A second arc is has a radius of about0.030 inch to about 0.050 inch. At the center of the staple pockets 190,the first and second arcs intersect. The distance between the two pairedcups is from about one times the radius of the staple wire to about twotimes the radius of the stapler wire. The transverse shape of the 2-Dpocket is created by parabolic arcs that intersect with the longitudinalarcs to create a rectangular shaped cut into the surface of the pocket.The rectangular-shaped cut is about four times to about six times thediameter of the staple wire and the length is about half of the radiusto about one times the radius of the span of the crown of the staple.Pocket shapes according to embodiments of the present invention may besized for staples having any crown length, wire diameter, and leglength. In this manner, the bent tips will not cross the midline of thecrowns of the staples 198. In one embodiment, and with reference toFIGS. 38A and 38B where there is a gap increase between the anvil andthe cartridge in the transverse plane (transverse to the longitudinaldirection), both of the leading (distal) and lagging (proximal) staplelegs will be deflected to the same side of the crown (shown in FIG.38B). Consequently, the legs of the staples 198 may cross.

In embodiments of the end effector, where there is a gap increasebetween the anvil and the cartridge, for example, like that shown inFIG. 11, the leading leg of each staple 198 will contact the leadingpocket and begin bending before the lagging leg contacts the laggingpocket when the surgeon fires the stapling mechanism. With reference toFIGS. 39A-40B, the staple pockets 190 may be configured to bend theleading leg so that it is out of the way of the lagging leg when thelagging leg crosses the leading leg. In this manner, the trajectory ofthe bent second leg is not interrupted by collision with the alreadybent leading leg. Those of ordinary skill in the art will recognize thatother alternative arrangements may also be possible to prevent the tipsof the staple legs from crossing below the staple crowns.

As discussed above, the portion of the stomach being resected is oftenstapled along with the stomach sleeve to prevent undesirable leakage ofcontents therefrom. With reference to FIG. 41, an exemplary embodimentincludes the endocutter stapling device 100 described above withreference to FIG. 3 and a clamp 610. Before actuation of the endocutterstapling device 100, the clamp 610 may be clamped onto the tissueadjacent the endocutter stapling device 100 that will be excised afterthe staple line is complete. In other words, the clamp 610 may be to theanatomical left of the endocutter stapling device 100. With thisconfiguration, stapling the to-be-excised portion of the stomach 10would not be necessary due to the compression provided by the clamp 610.In this regard, the endocutter stapling device 100 may be configured toonly staple the tissue that will become the stomach sleeve. The clampingforce provided by the clamp 610 may supplement the clamping forceprovided by the endocutter stapling device 100. This additionalcompression near the cut line may result in an improved staple line.After the staple line is complete, the excised portion would still beclamped by the clamp 610, as shown in FIG. 41.

In one embodiment of the present invention, with reference to FIG. 42, aspacer 620 may be coupled to the anvil 42 of the endocutter staplingdevice 100. The spacer may have a width of, for example, about 1 cm. Thestaple line 12 is frequently 1 cm away from the gastro esophagealjunction 22, and using the spacer 620 to space the endocutter staplingdevice 100 apart from the gastro esophageal junction 22 would assure aproper spacing from this anatomical landmark. Properly spacing theendocutter stapling device 100 from the gastro esophageal junction 22ensures that staples are not formed on a part of the esophagus. Whilethe spacer 620 is specifically shown as being coupled to the anvil 42,it would be readily appreciated that in alternate embodiments, thespacer 620 may alternatively or additionally be coupled to the cartridge44.

While the present invention has been illustrated by a description ofvarious preferred embodiments and while these embodiments have beendescribed in some detail, it is not the intention of the inventor torestrict or in any way limit the scope of the appended claims to suchdetail. Further, it should be recognized that the spacing and scale ofcertain elements depicted in the Figures may be exaggerated to aid inthe understanding of the present invention. Consequently, the Figuresmay be seen as schematic representations rather than exactrepresentations of embodiments. Though the embodiments described hereinwere primarily directed to a stapler, it is clear that many of theaspects of the present invention may be utilized with additionaldevices. By way of example, the embodiments described herein may operateas a surgical clamp or a stabilizing device independent of the aspectsof the present invention that allow the embodiments to act as a stapler.Additional advantages and modifications will readily appear to thoseskilled in the art. The various features of the invention may be usedalone or in any combination depending on the needs and preferences ofthe user.

What is claimed is:
 1. An end effector for a medical device, the endeffector comprising: an anvil that includes a first end, a second end,and a first face; a cartridge that is operably configured to house aplurality of staples and that includes a first end, a second end, and asecond face, the first end of the cartridge being movably coupled to thefirst end of the anvil and the second end of the cartridge being movablycoupled to the second end of the anvil, the anvil being movable relativeto the cartridge to define a first gap between the first face and thesecond face at the first end of the anvil and the first end of thecartridge that is differently sized from a second gap between the firstface and the second face at the second end of the anvil and the secondend of the cartridge; and a tensioning mechanism configured toselectively move at least one of the anvil or the cartridge relative toeach other and control the first gap and the second gap, the tensioningmechanism comprising a pin and a flexible member, the flexible memberrouted around the pin and operably coupled to the anvil and thecartridge.
 2. The end effector of claim 1, wherein the first gap is fromabout 1.5 mm to about 3.3 mm.
 3. The end effector of claim 1, whereinthe second gap is from about 2.0 mm to about 5.0 mm.
 4. The end effectorof claim 1, wherein the first end of the anvil and the first end of thecartridge define a distal end of the end effector and the second end ofthe anvil and the second end of the cartridge define a proximal end ofthe end effector.
 5. The end effector of claim 1, wherein at least oneof the first face and the second face has a stepped configurationincluding a first segment and a second segment that are offset from oneanother, the first segment defining the first gap and the second segmentdefining the second gap.
 6. The end effector of claim 5, wherein thecartridge includes a plurality of staples and an open leg length of eachof the plurality of staples in each segment is the same.
 7. The endeffector of claim 5, wherein the cartridge includes a first stapledriver and a second staple driver, wherein a height of the first stapledriver is different in a direction from a height of the second stapledriver in a direction from the first end of the cartridge to the secondend of the cartridge.
 8. The end effector of claim 5, wherein thecartridge includes a first staple having an open leg length and beingpositioned in the first segment and a second staple having an open leglength and being positioned in the second segment, wherein the open leglength of the first staple is differently from the open leg length ofthe second staple.
 9. The end effector of claim 8, wherein the open leglength of the first staple and the open leg length of the second stapleare randomly distributed.
 10. The end effector of claim 8, wherein adistribution of the open leg length of the first staple and the open leglength of the second staple is operably sized based on a probable tissuethickness along an anatomical structure.
 11. The end effector of claim5, wherein the cartridge includes a plurality of staples, the pluralityof staples being divided into a first zone of staples and a second zoneof staples, the plurality of staples being arranged in at least one rowand at least one column in each of the first zone of staples and thesecond zone of staples, wherein an open leg length of a staple in thefirst zone of staples is different from an open leg length of a secondstaple in the second zone of staples.
 12. The end effector of claim 5,wherein the cartridge includes a plurality of staples, the cartridgehaving a first edge and a second edge, the plurality of staples beingdivided into a first zone of staples adjacent the first end and a secondzone of staples being adjacent the second edge, wherein the first zoneof staples has a first open leg length and the second zone of stapleshas a second open leg length, where the first open leg length isdifferent from the second open leg length.
 13. The end effector of claim1, wherein the cartridge includes a plurality of staples divided into afirst zone of staples and a second zone of staples, and a gauge of afirst staple in the first zone of staples is different from a gauge of asecond staple in the second zone of staples.
 14. The end effector ofclaim 1, wherein the cartridge includes a plurality of magazinesconfigured to be selectively inserted and removed from the cartridge,each magazine including a plurality of staples arranged in one or morerows and one or more columns.
 15. The end effector of claim 1, whereinthe end effector includes an alignment mechanism configured tofacilitate alignment between the anvil and the cartridge as the anvil ismoved toward the cartridge.
 16. The end effector of claim 1, wherein thefirst flexible member movably couples the second end of the anvil to thesecond end of the cartridge.
 17. The end effector of claim 16, whereinthe flexible member movably couples the first end of the anvil to thefirst end of the cartridge.
 18. The end effector of claim 17, whereinproximal movement of the pin relative to the end effector withdraws atleast a portion of the flexible member from the end effector.
 19. Theend effector of claim 18, wherein the flexible member has a first end, asecond end, and a central portion extending therebetween, wherein thefirst end of the flexible member is anchored to one of the first end ofthe cartridge and the first end of the anvil, wherein the second end ofthe flexible member is anchored to one of the second end of thecartridge and the second end of the of the anvil, and wherein thecentral portion of the flexible member is routed around the pin.